[Merged by Bors] - feat(RingTheory): construct etale neighborhood that isolates point in fiber

[erdOne]

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[github-actions]

PR summary bfbfe1fa73

Import changes for modified files

No significant changes to the import graph

Import changes for all files

Files	Import difference
Mathlib.RingTheory.Etale.QuasiFinite (new file)	1661

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Declarations diff

+ Algebra.exists_etale_isIdempotentElem_forall_liesOver_eq
+ Ideal.comap_fiberIsoOfBijectiveResidueField_apply
+ Ideal.comap_fiberIsoOfBijectiveResidueField_symm
+ Ideal.eq_of_comap_eq_comap_of_bijective_residueFieldMap
+ Ideal.exists_not_mem_forall_mem_of_ne_of_liesOver
+ Ideal.fiberIsoOfBijectiveResidueField
+ UniversalCoprimeFactorizationRing.exists_liesOver_residueFieldMap_bijective
+ _root_.Algebra.exists_etale_bijective_residueFieldMap_and_map_eq_mul_and_isCoprime.{u}
+ _root_.IsArtinianRing.exists_not_mem_forall_mem_of_ne
+ comapEquiv_symm
+ toPiLocalization_bijective

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.

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No changes to technical debt.

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).

[jcommelin]

Thanks 🎉

bors merge

[mathlib-bors]

Pull request successfully merged into master.

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