2026.4.3

What's Changed

• Fix linkcheck by @connorjward in #5430
• Pin the hypre cycle and assert on the condition number by @pbrubeck in #5411
• Port firedrake-preprocess-bibtex to bibtexparser 2 by @pbrubeck in #5439
• Minor edits to AGENTS.md by @pbrubeck in #5441
• Make the docs notebook build incremental and cheap by @pbrubeck in #5440
• Test that control checkpoints survive recompute by @stephankramer in #5157
• Fix CI runner permissions issues by setting HOME by @connorjward in #5465
• Add information about PR tags to contributing page by @connorjward in #5450
• import pyadjoint.TAOSolver into firedrake.adjoint namespace by @JHopeCollins in #5481
• Accept appctx as a keyword argument of solve(A, x, b) by @sghelichkhani in #5456

Full Changelog: 2026.4.2...2026.4.3