Remove PROPERTY_HINT_IMAGE_COMPRESS constants

[Mickeon]

Removes PROPERTY_HINT_IMAGE_COMPRESS_LOSSY and PROPERTY_HINT_IMAGE_COMPRESS_LOSSLESS. These do not actually do anything, at all. These were used in 3.x, but are no longer necessary now.

[nikitalita]

What about lossy-compressed webps? Textures can still be encoded as those.

[Mickeon]

What about lossy-compressed WEBPs? Textures can still be encoded as those.

Don't worry, these are not import options. I reiterate, these property hints do not do anything in the engine.

[Mickeon]

This PR's failing check has made me discover that PROPERTY_HINT_INT_IS_POINTER and PROPERTY_HINT_ARRAY_TYPE are exposed in the wrong order and should be swapped. Putting it out here as a mental note.

[nikitalita]

I am sorry, I had thought that this also removed COMPRESS_LOSSLESS and COMPRESS_LOSSY; those values would remain unchanged and those are still encoded in the texture. The PropertyHint is only set after the resource is imported. I withdraw my objection.

[nikitalita]

After some searching through the code, I don't see any Object that encodes PropertyHint directly into a resource. I don't think this will break any Godot resources; it might break resources in extensions that do that, though. It might also break third-party editor tools that rely on the PropertyHint enum they get from the language server directly.

In either case, the enum values started changing back in April, here: #60458

At the time, It was decided to just merge and cleanup later. So I guess that's something to worry about later? 🤷

[akien-mga]

Approved in PR review meeting, those are unused (also unused in 3.x but we don't want to break compat there).

[Mickeon]

Rebased.

[akien-mga]

Thanks!