[WebAPI] Enable WebGPU in Nightly by default

[Rumyra]

Acceptance Criteria

• The listed features are documented sufficiently on MDN
• BCD is updated
• Interactive example and data repos are updated if appropriate
• The content has been reviewed as needed

For folks helping with Firefox related documentation

• 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

Related Gecko bugs

https://bugzilla.mozilla.org/show_bug.cgi?id=1746245 @chrisdavidmills has just documented this, so it should just be experimental features & bcd - wondering if @queengooborg can help out with bcd

Other

• Check content open issues to see if any pertain to the subject matter. If there are any that can be closed because of the work, do so. If there are any that can be fixed relatively quickly because of the knowledge from completing this issue and you have time, feel free to go ahead and fix them.
• Check if glossary updates are required for the feature you're documenting - whether an existing term needs to be updated or a new term should be added.
• Check if BCD update means that content pages need to have experimental markup removed or deprecated markup added (front matter tags and macros).

[hamishwillee]

Yes, though BCD is proving tough - i.e. working out what FF really supports is not obvious in all cases from the IDL.

Status

• BCD - FF113 supports WebGPU on nightly browser-compat-data#19370
• Experimental features - FF113 Experimental Features - WebGPU on nightly #26267
• Docs
  • Structure clone serializable types -Don't need to update with serializable ones yet as serialization not yet deployed on any browser (will eventually need updates for GPUCompilationMessage, GPUCompilationInfo, GPUPipelineError, GPUCompilationMessage, GPUCompilationInfo.)
  • Add security / secure-context info: WebGPU - Add secure context info #26268
• dev-doc-complete

This is done, though waiting on merge of BCD