Fix misspellings in app/spec comments

What does this MR do?

Fixes misspellings in app/spec comments, which are not executed at all.

• /doc (!25505 (merged))
• /app, /spec comments (THIS MR)
• /app, /spec non-comments (!25521 (merged))

Does this MR meet the acceptance criteria?

• [n/a] Changelog entry added, if necessary
• [n/a] Documentation created/updated via this MR
• Documentation reviewed by technical writer or follow-up review issue created
• [n/a] Tests added for this feature/bug
• [n/a] Tested in all supported browsers
• Conforms to the code review guidelines
• [n/a] Conforms to the merge request performance guidelines
• Conforms to the style guides
• [n/a] Conforms to the database guides
• [n/a] Link to e2e tests MR added if this MR has Requires e2e tests label. See the Test Planning Process.
• [n/a] Security reports checked/validated by reviewer