perf( Mathlib/CategoryTheory/Sites/LocallySurjective.lean): investigate removing transitive import

[grunweg]

#41222 exposed that removing one transitive import makes mathlib 300 * 10⁹ instructions slower (about 0.2%).
Let's confirm this in isolation - and if so, investigate! That's too large a performance cliff to ignore.

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[grunweg]

!bench

[leanprover-radar]

Benchmark results for f489137 against db5c6a6 are in. No significant results found. @grunweg

• 🟥 build//instructions: +36.5G (+0.02%)

No significant changes detected.

[github-actions]

PR summary f489137514

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 (regex)

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

You can run this locally as follows

## from your `mathlib4` directory:
git clone https://github.com/leanprover-community/mathlib-ci.git ../mathlib-ci

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

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

The doc-module for scripts/pr_summary/declarations_diff.sh in the mathlib-ci repository contains some details about this script.

Declarations diff (Lean)

✅ Lean-aware diff — post-build, computed from the Lean environment (commit f489137).

• +0 new declarations
• −0 removed declarations

No declaration differences.

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No changes to strong technical debt.

No changes to weak technical debt.

Current commit f489137514
Reference commit db5c6a6667

This script lives in the mathlib-ci repository. To run it locally, from your mathlib4 directory:

git clone https://github.com/leanprover-community/mathlib-ci.git ../mathlib-ci
../mathlib-ci/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).

[grunweg]

Hm, strange. #41411 tries the same on top of #41222.