This PR was squashed before being merged into the 4.4 branch. Discussion ---------- [FrameworkBundle] Dont store cache misses on warmup | Q | A | ------------- | --- | Branch? | 4.4 | Bug fix? | yes | New feature? | no | Deprecations? | no | Tickets | Fix #38694 | License | MIT | Doc PR | symfony/symfony-docs#15172 When we are warming the annotation cache, we are reading all annotation into an `ArrayAdapter`. When we are done we move the values to a `PhpArrayAdapter` to store them in a file. @Seldaek [found out](#38694 (comment)) that when you are using a custom constraint with a `Symfony\Component\Validator\Constraints\Callback`, there is a strange error like: > Can use "yield from" only with arrays and Traversables That is because the `Closure` in the `Symfony\Component\Validator\Constraints\Callback` cannot be serialised and saved to cache. But since the `ArrayAdapter` is also [storing misses as null](#35362), the null values are understood as real values. When all values are moved to the `PhpArrayAdapter` and we ask the cache for a value (via Doctrine's `CacheProvider`), it will return `null` as a value instead of `false` as a cache miss. And `null` is not something one could "yield from". Commits ------- 27a22b3 [FrameworkBundle] Dont store cache misses on warmup

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