[Merged by Bors] - chore(Algebra/Category): add ModuleCat.restrictScalarsIsoOfEquiv

[chrisflav]

Extracted from #37766 as a separate PR, because it also contains three basic simp lemmas.

We also add missing type annotations in the file Mathlib/Algebra/Category/ModuleCat/ChangeOfRings.lean.

---

[github-actions]

PR summary c60f516525

Import changes for modified files

No significant changes to the import graph

Import changes for all files

Files	Import difference

---

Declarations diff

+ RingHom.toModule_smul
+ coe_coe_toAddEquiv_symm
+ coe_coe_toEquiv_symm
+ coe_coe_toMulEquiv_symm
+ instance {R S : Type*} [Ring R] [Ring S] (f : R →+* S) : (restrictScalars f).Additive
+ instance {R₀ R S : Type*} [CommSemiring R₀] [Ring R] [Ring S] [Algebra R₀ R] [Algebra R₀ S]
+ restrictScalarsIsoOfEquiv
+ restrictScalarsIsoOfEquiv_hom_apply
+ restrictScalarsIsoOfEquiv_inv_apply
- instance {R S} [Ring R] [Ring S] (f : R →+* S) : (restrictScalars f).Additive
- instance {R₀ R S} [CommSemiring R₀] [Ring R] [Ring S] [Algebra R₀ R] [Algebra R₀ S]

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.

---

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).

[robin-carlier]

Thanks!

maintainer merge

[github-actions]

🚀 Pull request has been placed on the maintainer queue by robin-carlier.

[riccardobrasca]

Can you improve the PR message? You say "split off", but it's not clear what you are talking about. Thanks!

bors d+

[mathlib-bors]

✌️ chrisflav can now approve this pull request. To approve and merge a pull request, simply reply with bors r+. More detailed instructions are available here.

[chrisflav]

I think I have clarified the PR description. Thanks for the reviews!
bors r+

[mathlib-bors]

Pull request successfully merged into master.

Build succeeded:

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