Optional $post and $post_id should be documented as such

[DrewAPicture]

In [25567] some usage of $post_id and/or $post were un-marked as optional as they rely on the post global.

These (and others in core) need to be marked as optional, also notating that they default to the post global via get_post() where applicable.

Related-ish: #20495

[DrewAPicture]

Looks like [28653] missed posting. It handled properly documenting $post as optional where applicable.

[DrewAPicture]

In 28654:

Ensure $post_id is documented as optional where applicable.

See #28388.

[DrewAPicture]

In 28655:

Be more specific that $post_id does not default to the ID of the global $post in some cases.

See [28654]. See #28388.

[DrewAPicture]

In 28975:

Fix an incomplete docblock for wp_create_categories() as part of $post/$post_id cleanup.

See #28388.

[DrewAPicture]

In 28976:

Remove backticks on $post variables in some short parameter descriptions.

See [28653], [28654].
See #28388.

[DrewAPicture]

That should cover it for now. Any others we can get in the full file audits.