chore: golf using grind

[euprunin]

The goal of this PR is to decrease the number of times lemmas are called explicitly. Any decrease in compilation time is a welcome side effect, although it is not a primary objective.

Trace profiling results (differences <30 ms considered measurement noise):

• ✅️ SimpleGraph.Walk.IsPath.getVert_injOn: unchanged 🎉
• ✅️ SimpleGraph.Walk.length_bypass_le: unchanged 🎉
• ✅️ Rat.floor_intCast_div_natCast: unchanged 🎉
• ✅️ InnerProductGeometry.norm_eq_of_angle_sub_eq_angle_sub_rev_of_angle_ne_pi: unchanged 🎉
• ✅️ padicNorm.zero_of_padicNorm_eq_zero: unchanged 🎉

Profiled using set_option trace.profiler true in.

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[github-actions]

PR summary 0f8bcdff02

Import changes for modified files

No significant changes to the import graph

Import changes for all files

Files	Import difference

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Declarations diff

No declarations were harmed in the making of this PR! 🐙

You can run this locally as follows

## summary with just the declaration names:
./scripts/pr_summary/declarations_diff.sh <optional_commit>

## more verbose report:
./scripts/pr_summary/declarations_diff.sh long <optional_commit>

The doc-module for scripts/pr_summary/declarations_diff.sh contains some details about this script.

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No changes to technical debt.

You can run this locally as

./scripts/reporting/technical-debt-metrics.sh pr_summary

• The relative value is the weighted sum of the differences with weight given by the inverse of the current value of the statistic.
• The absolute value is the relative value divided by the total sum of the inverses of the current values (i.e. the weighted average of the differences).