Icons: Document breaking changes and fix issues from #71878

* Remove icon symlink from edit.svg to pencil.svg

* Document removal of `edit` and `warning` (removed in #71878)

* Also add a specific rule in `lint-staged` to generate icons any time
  the icons library is modified, thereby catching generation errors even
  in commits that don't modify JS/TS files. (Before this commit, the
  only way to catch errors was to commit JS/TS files, which would
  trigger the NPM `prelint` script, which would then call the icon
  generator.)

Author: mcsf

package.json

@@ -296,6 +296,9 @@
 			"node ./bin/api-docs/are-api-docs-unstaged.js",
 			"node ./bin/packages/lint-staged-typecheck.js"
 		],
+		"packages/icons/src/library/*": [
+			"npm run -w packages/icons build"
+		],
 		"**/tsconfig.json": [
 			"npm run lint:tsconfig"
 		]

packages/icons/CHANGELOG.md

@@ -2,7 +2,7 @@
 
 ## Unreleased
 
-- Non-breaking, but major change: Switch to SVG icons as canonical source format, letting the system auto-generate the React elements and index. ([#71878](https://github.com/WordPress/gutenberg/pull/71878))
+- Breaking change: Remove `edit` and `warning` icons, which were aliases to `pencil` and `cautionFilled`, respectively. Switch to SVG icons as canonical source format, letting the system auto-generate the React elements and index. ([#71878](https://github.com/WordPress/gutenberg/pull/71878)).
 
 ## 10.32.0 (2025-10-01)