[WebAPI] Remove AppCache

[chrisdavidmills]

Acceptance criteria

1. • [x] The listed features are documented sufficiently on MDN
2. • [x] BCD is updated
3. • [x] Interactive example and data repos are updated if appropriate - Not applicable
4. • [x] The content has been reviewed as needed

Features to document

1. Removal of AppCache

Related Gecko bugs

1. • [x] Disable appcache in release — nice to finally get rid of this! We mainly just need to update BCD, and think about if there is anything else we want to remove.

For folks helping with Firefox-related documentation features — make sure above AC have been done, but also:

• Set bugs to dev-doc-complete
• Add entry to Firefox release notes if feature is enabled in release
• Add entry to Firefox experimental features page if feature is not yet enabled in release

[hamishwillee]

1. • [x] The listed features are documented sufficiently on MDN
     • • [x] Using the application cache - only relevant doc
       • I updated note to say "do not use" (rather than just strong recommendation) and that feature is "removed in FF84". The note is now up the top of the page ahead of the deprecation macros, because to my mind it is more important than those.
       • Added "further info" link to useful blog https://web.dev/appcache-removal/
2. • [x] BCD is updated - done.
3. • [x] Interactive example and data repos are updated if appropriate.
     • Not applicable (none present)
4. • [x] The content has been reviewed as needed
5. • [x] Set bugs to dev-doc-complete
   • I added note about changes here, but @chrisdavidmills you will need to add the labels dev-doc-complete
6. • [x] Firefox Release notes - added to API > removals section.
7. • [x] Add entry to Firefox experimental features page if feature is not yet enabled in release
     • Not applicable - was prematurely removed in January by Sebastitian

@chrisdavidmills This is ready for review. Note

• You will need to add dev-doc-complete
• Out of scope for me, but this appnote: Appcache is showing up as uncached or disabled - says that from FF84 you can no longer enable. I doubt that is correct.

[Rumyra]

This all looks great to me 👍 thank you @hamishwillee !

I agree about the support article. I am running 84 and can still flip the pref.

[chrisdavidmills]

This is looking great, thanks @hamishwillee .

The only extra thing I did was to update https://wiki.developer.mozilla.org/en-US/docs/Web/API/Service_Worker_API/Using_Service_Workers#The_premise_of_service_workers — the note talked about AppCache still being available.

Closing!

[hamishwillee]

Thanks. How did you find that mention of AppCache? Just knowing it might be mentioned? Normally I try search to find these things, but not all that reliable on MDN.

[chrisdavidmills]

I just know about it because I wrote it ;-)