[Merged by Bors] - chore: group public and private imports

[kim-em]

Group public imports before private imports, with a blank line between the groups, in 2,076 Mathlib files. Preserve the order within each group, import modifiers, and comments. No imports are removed or have their visibility changed.

Generated using the formatter in #44503. This is a source-only cleanup and can merge independently of the linter implementation.

Supersedes #42063.

[github-actions]

PR summary 24c474eca1

Import changes for modified files

No significant changes to the import graph

Import changes for all files

Files	Import difference

---

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 24c474e).

• +0 new declarations
• −0 removed declarations

No declaration differences.

---

No changes to strong technical debt.
No changes to weak technical debt.

Current commit 24c474eca1
Reference commit 7d6757bc18

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).

[sgouezel]

bors r+

[mathlib-bors]

Pull request successfully merged into master.

Build succeeded:

• ci (staging) / Test and lint
• ci (staging) / Post-CI job
• ci (staging) / Lint style
• ci (staging) / Build
• ci (staging) / Post-Build Step