chore: avoid unnecessary change tactics

[kim-em]

change is always a bit of smell, so in cases where simp can just close the goal unassisted, do that.

[kim-em]

Another one thanks to @dwrensha's tryAtEachStep project.

[github-actions]

PR summary 0644c2101a

Import changes for modified files

No significant changes to the import graph

Import changes for all files

Files	Import difference

---

Declarations diff

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

You can run this locally as follows

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

## more verbose report:
./scripts/declarations_diff.sh long <optional_commit>

The doc-module for script/declarations_diff.sh contains some details about this script.

---

Decrease in tech debt: (relative, absolute) = (3.00, 0.00)

Current number	Change	Type
3373	-3	porting notes

Current commit 0644c2101a
Reference commit a221dba44a

You can run this locally as

./scripts/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).

[Ruben-VandeVelde]

maintainer merge

[github-actions]

🚀 Pull request has been placed on the maintainer queue by Ruben-VandeVelde.

[bryangingechen]

!bench

[leanprover-bot]

Here are the benchmark results for commit 377edfc.
The entire run failed.
Found no significant differences.

[eric-wieser]

I worry that dropping the change makes these proofs less maintainable, as if simp starts failing we've thrown away the human-written clue about the expected proof. Using suffices as I suggest above means we can keep the clue, but drop the dependence on the defeq (if that's desirable)

[kim-em]

@eric-wieser, do you see other changes here which are helping readability? I'm happy to revert those or replace them with suffices.

[eric-wieser]

This one can probably just become exact (map_div e t.2 t.1).symm

[kim-em]

But simp is better, no?

[j-loreaux]

the build is failing

[j-loreaux]

Sorry, looks like there's yet another merge conflict:

bors d+

[mathlib-bors]

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