fix: add a missing check for 'inject-field' diagnostics

[NeOzay]

fix related to #2746

[tomlau10]

Glad that you finally find a proper way to fix it 😄

---

And as @C3pa mentioned here, I tested your fix on a few similar issues and all of them are cleared now! One stone three birds! 🎉

• Invalid fields injected warning #2341
• False-Positive Inject-Field diagnostic suggests duplicate ---@class statement #2528
• Assigning to fields not defined through annotations in classes leads to inject-field diagnostics #2303

In your PR description, instead of fix related to #2746, I think you should write it as:

fixes #2746, fixes #2341, fixes #2528, fixes #2303

Only then can properly link the pull request to those issues, and leverage the github's close issue on PR merge function. It requires the keywords (in your case is the word fix) to be immediately before the issue number.

[carsakiller]

@tomlau10 Thanks for mentioning all the fixed issues! Helps a bunch with organization! I linked them to this PR 🙂.

[sumneko]

Thank you!