Fix uid:// paths fail to load at editor startup

[Hilderin]

• Fixes uid:// Paths Fail to Load at Editor Startup #95562
• Fixes Almost all usages of preload with UID path result in error upon startup #95535

The issue was caused by a call deferred to ResourceUID::get_singleton()->clear in the constructor of EditorFileSystem. Now that the plugin are created after the creation of EditorFileSystem the uid loaded from cache were removed before the plugins were created in the first scan process.

Note: Even in 4.2.2 when the uid cache file uid_cache.bin is missing, the same error occurs: Condition "!unique_ids.has(p_id)" is true because the uid are loaded only from the cache before the plugins are created. The same problem still occurs with this PR and short of scanning all the .import files before loading the plugins just for the uid, I don't see an solution for that.

Edit: Added the issue #95535

[akien-mga]

Might also solve #95535 which may be a duplicate of the other issue, CC @TheDuriel.

[Hilderin]

Indeed, I tested this PR with the MRP from #95535 (comment) and the issue is fixed. Same here, the first time loading the project, I got the errors and restarting the editor fixes them.

[TheDuriel]

Will gladly test if someone can provide a windows build. Still suffering build errors on my end.

[Hilderin]

@TheDuriel
You can always find built executable (artifact) for each PR on Github. I don't know if there's an easier way to access them, but I use the Checks tab:

Click on summary link on the left:

At the bottom you have all the artifacts:

For windows:
https://github.com/godotengine/godot/actions/runs/10431889561/artifacts/1822912370

[TheDuriel]

Awesome.

Can confirm then, this PR fixes all my errors, including ones not caused by autoloads.

[mpewsey]

Looks good from my standpoint on #95562 as well.

Thanks for taking the time to fix this 😄

[akien-mga]

Thanks!

[akien-mga]

Cherry-picked for 4.3.1.