RuntimeDataDescriber: Support dynamically describing arbitrary enums (#6039)

Previously, we were using codegen to support describing a fixed set of enums.

Instead, we implement an enum() function, allowing any native PHP enum to be described.
All enums used in runtime data have been migrated to native PHP 8.1 enums in minor-next to facilitate this.

This implementation:

- is faster (in extreme cases by 40x, such as with PotionType)
- requires way less code
- does not require a build step
- is way more flexible

This fixes #5877, increasing the range of stuff that plugins are now able to do.

EnumTrait enums are not supported, as it's easier and cleaner to just support native enums. Most core EnumTrait enums have been migrated to native enums by now to facilitate this.

.github/workflows/main.yml

@@ -152,9 +152,6 @@ jobs:
       - name: Regenerate KnownTranslation APIs
         run: php build/generate-known-translation-apis.php
 
-      - name: Regenerate RuntimeEnum(De)serializer
-        run: php build/generate-runtime-enum-serializers.php
-
       - name: Regenerate BedrockData available files constants
         run: php build/generate-bedrockdata-path-consts.php