The tmLanguage `injectionSelector` has broken in v1.9.2

[edheltzel]

Type: Bug Does this issue occur when all extensions are disabled?: Yes

• VS Code Version: 1.92.0
• OS Version: macOS 14.5 23F79 arm64 (apple m1 max)

I maintain an extension called Better Nunjucks. It uses tmLanguage's injectionSelector to specify "the scope in which a particular grammar should be injected. This feature allows for embedding one grammar within another based on specific conditions, enhancing the syntax highlighting capabilities for complex language constructs." This choice was made to avoid setting files.association for Nunjucks/HTML/Markdown files.

With the release of v1.92 - the Better Nunjucks syntax highlighting has broken. I can confirm that with v1.91.1 the extension functions as expected.

Steps to Reproduce:

1. Install and enable Better Nunjucks
2. Open a project with Nunjucks files

Images for context:

v1.91.1	v1.92

Seen on https://github.com/edheltzel/nunjucks-for-visual-studio-code/issues/21

[edheltzel]

@aeschli, I ended up resolving this on my end - PR #22: Better Nunjucks for VSCode