ci: delete CI-generated branches

[samestep]

Description

This PR adds a daily cron job using https://github.com/dawidd6/action-delete-branch to automatically delete the ci/refs/pull/*/merge branches created by #988, now that the autogenerated PR comment links to commits instead of branches as of #1313.

Checklist

• I have commented my code, particularly in hard-to-understand areas
• I have reviewed any generated registry diagram changes

[github-actions]

± Registry diff

📊 Performance

Key

Note that each bar component rounds up to the nearest 100ms, so each full bar is an overestimate by up to 400ms.

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name ▝▀▀▀▀▀▀▀▀▀▀▀▚▄▄▄▄▄▄▄▄▄▞▀▀▀▀▀▀▀▀▀▀▀▀▚▄▄▄▄▄▄▄▄▄▖
      compilation labelling optimization rendering

Data

                                                                  0s   1s   2s   3s   4s   5s   6s
                                                                  |    |    |    |    |    |    |
3d-projection-fake-3d-linear-algebra                              ▝▞▖
acquaintanceship-graph-simple-graph                               ▝▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▞▀▀▀▀▀▀▖
allShapes-allShapes                                               ▝▚▚▄▄
angle-equivalence-triangle-mesh-2d                                ▝▀▀▞▀▚
arrowheads-arrowheads                                             ▝▞▖
caffeine-structural-formula                                       ▝▀▀▚▚
call-directed-graph-directed-multigraph                           ▝▀▀▀▀▀▀▞▀▚
call-undirected-graph-pseudograph                                 ▝▀▀▀▀▚▀▖
center-shrink-circle-animation                                    ▝▞▖
circle-example-euclidean                                          ▝▀▚▚
closest-point-test-closest-point                                  ▝▀▀▀▀▀▀▚▚
collinear-euclidean                                               ▝▀▞▖
communications-network-one-way-links-graph-simple-directed-graph  ▝▀▀▀▀▀▚▀▖
complete-bipartite-graphs-simple-graph                            ▝▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▞▀▀▚
complete-graphs-simple-graph                                      ▝▀▀▀▀▀▀▀▀▀▀▀▞▀▚
computer-network-diagnostic-links-graph-pseudograph               ▝▀▀▀▀▚▚
computer-network-graph-simple-graph                               ▝▀▀▀▚▚
computer-network-multiple-links-graph-pseudograph                 ▝▀▀▀▀▚▀▚
computer-network-multiple-one-way-links-graph-directed-multigraph ▝▀▀▀▀▀▀▀▞▚
concyclic-pair-triangle-mesh-2d                                   ▝▀▞▖
congruent-triangles-euclidean                                     ▝▀▀▚▚
continuousmap-continuousmap                                       ▝▞▖
cotan-formula-triangle-mesh-2d                                    ▝▀▞▖
cube-graphs-simple-graph                                          ▝▀▀▀▀▀▀▀▀▀▀▀▞▀▖
cubic-bezier-cubic-bezier                                         ▝▀▞▀▖
cycle-graphs-simple-graph                                         ▝▀▀▀▀▀▀▚▀▚
glutamine-molecules-basic                                         ▝▀▚▚
half-adder-distinctive-shape                                      ▝▚▚
halfedge-mesh-triangle-mesh-2d                                    ▝▀▞▖
hybrid-topology-graph-simple-graph                                ▝▀▀▞▖
hypercube-network-graph-simple-graph                              ▝▀▀▀▀▚▚
hypergraph-hypergraph                                             ▝▀▀▀▞▀▀▀▀▀▀▀▚
incenter-triangle-euclidean                                       ▝▀▞▖
influence-graph-simple-directed-graph                             ▝▀▀▞▖
jobs-trained-matching-graph-simple-graph                          ▝▀▀▀▀▞▚
jobs-trained-no-matching-graph-simple-graph                       ▝▀▀▀▞▖
lagrange-bases-lagrange-bases                                     ▝▚▚
linear-array-graph-simple-graph                                   ▝▀▚▚
lines-around-rect-rect-line-dist                                  ▝▚▚
matrix-matrix-addition-matrix-ops                                 ▝▚▚
matrix-matrix-division-elementwise-matrix-ops                     ▝▚▚
matrix-matrix-multiplication-elementwise-matrix-ops               ▝▚▚
matrix-matrix-multiplication-matrix-ops                           ▝▀▞▖
matrix-matrix-subtraction-matrix-ops                              ▝▚▚
matrix-transpose-matrix-ops                                       ▝▚▚
matrix-vector-left-multiplication-matrix-ops                      ▝▚▚
matrix-vector-right-multiplication-matrix-ops                     ▝▚▚
mesh-network-graph-simple-graph                                   ▝▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▚▀▀▀▀▀▀▀▀▀▀▀▖
midsegment-triangles-euclidean                                    ▝▀▞▖
mobius-mobius                                                     ▝▚▚
module-dependency-graph-simple-directed-graph                     ▝▀▀▀▚▀▖
niche-overlap-graph-simple-graph                                  ▝▀▀▀▀▀▞▖
nitricacid-lewis                                                  ▝▀▀▞▀▖
non-convex-non-convex                                             ▝▀▞▖
one-water-molecule-atoms-and-bonds                                ▝▞▖
parallel-lines-euclidean                                          ▝▀▞▖
persistent-homology-persistent-homology                           ▝▀▀▞▀▀▀▀▀▀▀▚▖
points-around-line-shape-distance                                 ▝▀▞▖
points-around-polyline-shape-distance                             ▝▀▀▞▖
points-around-star-shape-distance                                 ▝▀▀▀▞▖
precedence-graph-simple-directed-graph                            ▝▀▀▀▞▖
protein-interaction-graph-simple-graph                            ▝▀▀▀▀▀▀▚▀▀▚
quaternion-group-group-theory-cayley-graph                        ▝▀▚▚
quaternion-group-group-theory-multiplication-table                ▝▀▀▀▚▄▚
relative-orientation-triangle-mesh-2d                             ▝▀▞▖
ring-topology-graph-simple-graph                                  ▝▀▞▖
round-robin-graph-simple-directed-graph                           ▝▀▀▀▀▚▚
scalar-vector-division-matrix-ops                                 ▝▚▚
scalar-vector-left-multiplication-matrix-ops                      ▝▚▚
scalar-vector-right-multiplication-matrix-ops                     ▝▚▚
siggraph-teaser-euclidean-teaser                                  ▝▀▚▚
star-topology-graph-simple-graph                                  ▝▀▚▚
tree-tree                                                         ▝▀▄▚
tree-venn                                                         ▝▀▚▚
tree-venn-3d                                                      ▝▀▞▄▄▖
triangle-centers-triangle-mesh-2d                                 ▝▚▚
two-triangles-triangle-mesh-3d                                    ▝▚▚
two-vectors-perp-vectors-dashed                                   ▝▚▚
union-graph-simple-graph                                          ▝▀▀▚▚
vector-vector-addition-matrix-ops                                 ▝▚▚
vector-vector-division-elementwise-matrix-ops                     ▝▚▚
vector-vector-multiplication-elementwise-matrix-ops               ▝▚▚
vector-vector-outerproduct-matrix-ops                             ▝▚▚
vector-vector-subtraction-matrix-ops                              ▝▚▚
vector-wedge-exterior-algebra                                     ▝▚▚
wet-floor-atoms-and-bonds                                         ▝▀▞▀▖
wheel-graphs-simple-graph                                         ▝▀▀▀▀▀▀▀▀▀▀▚▀▀▖
word-cloud-example-word-cloud                                     ▝▀▀▞▖
wos-laplace-estimator-walk-on-spheres                             ▝▀▚▚
wos-nested-estimator-walk-on-spheres                              ▝▀▀▀▞▀▖
wos-offcenter-estimator-walk-on-spheres                           ▝▀▚▀▖
wos-poisson-estimator-walk-on-spheres                             ▝▀▚▀▖