perf(Tactic/Positivity): run extensions in reducible transparency

[JovanGerb]

This PR makes it so that positivity extensions are executed at reducible transparency, which should help with proof maintainability, and gives a slight speedup.

• This does not affect the check of whether the goal is a positivity goal. So, 0 i < x is still considered a positivity goal, even though 0 i is not defeq to 0 at reducible transparency.
• The positivity extension for subtraction is checking that it has the right instance using isDefEq, so this has to be done at the implicit transparency. Apparently, this change causes positivity to succeed somewhere where it did not before.

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[github-actions]

PR summary 53072a60b9

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 53072a6).

• +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 53072a60b9
Reference commit 80cbd0498a

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.py 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).

[JovanGerb]

!radar

[leanprover-radar]

Benchmark results for 53072a6 against 80cbd04 are in. There are significant results. @JovanGerb

• ✅ build//instructions: -26.2G (-0.02%)

Large changes (1✅)

• ✅ build/module/Mathlib.Analysis.Normed.Field.Dense//instructions: -8.1G (-45.10%)

Medium changes (2✅)

• ✅ build/module/Mathlib.Combinatorics.SimpleGraph.Extremal.Zarankiewicz//instructions: -1.4G (-13.23%)
• ✅ build/module/Mathlib.RingTheory.Polynomial.GaussNorm//instructions: -1.9G (-6.41%)

Small changes (5✅, 1🟥)

• 🟥 build/module/Aesop.Builder.Basic//instructions: +26.7M (+1.48%)
• ✅ build/module/Mathlib.Analysis.Calculus.ContDiff.Bounds//instructions: -719.7M (-1.10%)
• ✅ build/module/Mathlib.Analysis.Convex.StoneSeparation//instructions: -424.2M (-4.10%)
• ✅ build/module/Mathlib.Analysis.InnerProductSpace.Orientation//instructions: -374.5M (-1.58%)
• ✅ build/module/Mathlib.NumberTheory.NumberField.CanonicalEmbedding.NormLeOne//instructions: -3.0G (-6.78%)
• ✅ build/module/Mathlib.Topology.VectorBundle.Riemannian//instructions: -1.4G (-2.18%)