minor #32600 [Debug] drop the component (nicolas-grekas)

This PR was merged into the 5.0-dev branch.

Discussion
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[Debug] drop the component

| Q             | A
| ------------- | ---
| Branch?       | master
| Bug fix?      | no
| New feature?  | yes
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | -
| License       | MIT
| Doc PR        | -

Of course, the component will still exist, but 4.4 will be the last version.
Use ErrorHandler now instead.

We will also have to drop the master branch on the subtree split.

Commits
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bd05642 [Debug] drop the component

composer.json

@@ -42,7 +42,6 @@
         "symfony/console": "self.version",
         "symfony/css-selector": "self.version",
         "symfony/dependency-injection": "self.version",
-        "symfony/debug": "self.version",
         "symfony/debug-bundle": "self.version",
         "symfony/doctrine-bridge": "self.version",
         "symfony/dom-crawler": "self.version",