refactor(Probability/Distributions/Uniform): change uniformOfFinset and ofMultiset from PMF to Measure

[EtienneC30]

Turn PMF.uniformOfFinset and PMF.ofMultiset into measures.

This is part of #42821 which deprecates PMF.

---

[github-actions]

PR summary 97960b4e7b

Import changes for modified files

No significant changes to the import graph

Import changes for all files

Files	Import difference

---

Declarations diff (regex)

+ ofMultiset_apply_singleton
+ ofMultiset_apply_singleton_of_notMem
+ uniformOfFinset_apply_singleton
+ uniformOfFinset_apply_singleton_of_mem
+ uniformOfFinset_apply_singleton_of_notMem
- mem_support_ofMultiset_iff
- mem_support_uniformOfFinset_iff
- mem_support_uniformOfFintype
- ofMultiset_apply
- ofMultiset_apply_of_notMem
- support_ofMultiset
- support_uniformOfFinset
- support_uniformOfFintype
- toMeasure_ofMultiset_apply
- toMeasure_uniformOfFinset_apply
- toMeasure_uniformOfFintype_apply
- toOuterMeasure_ofMultiset_apply
- toOuterMeasure_uniformOfFinset_apply
- toOuterMeasure_uniformOfFintype_apply
- uniformOfFinset_apply_of_mem
- uniformOfFinset_apply_of_notMem
- uniformOfFintype
- uniformOfFintype_apply

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 97960b4).

• +9 new declarations
• −6 removed declarations

+MeasureTheory.Measure.ofMultiset
+MeasureTheory.Measure.ofMultiset_apply_singleton
+MeasureTheory.Measure.ofMultiset_apply_singleton_of_notMem
+MeasureTheory.Measure.uniformOfFinset
+MeasureTheory.Measure.uniformOfFinset_apply
+MeasureTheory.Measure.uniformOfFinset_apply_singleton
+MeasureTheory.Measure.uniformOfFinset_apply_singleton_of_mem
+MeasureTheory.Measure.uniformOfFinset_apply_singleton_of_notMem
-PMF.ofMultiset
-PMF.ofMultiset.congr_simp
-PMF.uniformOfFinset
-PMF.uniformOfFinset.congr_simp
-PMF.uniformOfFinset_apply
-PMF.uniformOfFintype.congr_simp
+uniformOfFinset_apply

---

No changes to strong technical debt.

No changes to weak technical debt.

Current commit 97960b4e7b
Reference commit b948c053cf

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).