[Merged by Bors] - chore: use newly introduced finset notation

[YaelDillies]

For s : Finset α, replace s.card with #s, s.filter p with {x ∈ s | p x}, ∑ x ∈ s.filter p, f x with ∑ x ∈ s with p x, f x. Rewrap lines around and open the Finset locale where necessary.

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[github-actions]

PR summary a9d5fc119e

Import changes for modified files

No significant changes to the import graph

Import changes for all files

Files	Import difference

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Declarations diff

++-- card_Icc
++-- card_Ico
++-- card_Iio
++-- card_Ioc
++-- card_Ioo
++-- card_uIcc
++-- curryFinFinset
+-+- card_Iic
+-+- curryFinFinset_apply
+-+- curryFinFinset_apply_const
+-+- curryFinFinset_symm_apply
+-+- curryFinFinset_symm_apply_const
+-+- curryFinFinset_symm_apply_piecewise_const

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.

[kim-em]

bors merge

[mathlib-bors]

Pull request successfully merged into master.

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