fix: revert watchfiles to optional-dependency

[manzt]

• fix: revert watchfiles to optional-dependency
• chore: add changeset

[netlify]

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Name	Link
🔨 Latest commit	833cdd8
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[codecov]

Codecov Report

Merging #118 (d23aab8) into main (517c45a) will increase coverage by 0.02%.
The diff coverage is 100.00%.

❗ Current head d23aab8 differs from pull request most recent head 833cdd8. Consider uploading reports for the commit 833cdd8 to get more accurate results

@@            Coverage Diff             @@
##             main     #118      +/-   ##
==========================================
+ Coverage   98.46%   98.49%   +0.02%     
==========================================
  Files           7        7              
  Lines         392      398       +6     
==========================================
+ Hits          386      392       +6     
  Misses          6        6              

Impacted Files	Coverage Δ
anywidget/_util.py	100.00% <100.00%> (ø)

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