set trim_trailing_whitespace to false for inline snapshots

[Glyphack]

Summary

Some files have trailing whitespaces in the source code. I thought this was accidental but then realized it's on purpose because markdown is sensitive to whitespace.

Another solution I found to stop neovim from formatting these files on save is to set trim_trailing_whitespace to false for them. Without this change whenever you save that file any editor that supports EditorConfig it's gonna remove whitespaces and tests would fail.

Test Plan

[MichaReiser]

I think most trailing whitespace comes from the diagnostic rendering. I wonder if we should fix that instead. Let me put codex on this and see if it can come up with a fix. Otherwise, I think this is the right solution because it's super annoying otherwise.

[MichaReiser]

#24343 fixes most trailing whitespaces in code_actions. There's one remaining test that still uses trailing whitespaces after. I think the fix there is to not use inline snapshots for this specific test.

The other trailing whitespaces come from somewhere within our markdown rendering. I think we should take a look at whether those trailing whitespaces are necessary or can be replaced with another character.

[MichaReiser]

I merged a few PRs that:

• Fixed the rendering logic to not emit trailing whitespace
• Moved one off snapshots using trailing whitespace to external snapshots
• Replaced intentional trailing whitespace with an explicit marker ([ty] Replace markdown hard line breaks in snapshot tests #24361)

It should now (once all PRs are merged) no longer be necessary to disable trailing whitespace trimming for those files.