Tag nodes are now not allowed in mapping nodes, except if the mapping node has one element

[jbutA]

Describe the bug
Before the recent updates, mapping nodes could have tag nodes. Now this gives an error. Unless the mapping node has one element.

To Reproduce

Examples of it failing and not failing:
https://go.dev/play/p/ZiES84oWFCw

Expected behavior
Consistent behaviour one way or the other, regardless of number of elements.

Screenshots
If applicable, add screenshots to help explain your problem.

Version Variables

• Go version: [e.g. 1.23 ]
• go-yaml's Version: [e.g. v1.13.8 ]

Additional context
Add any other context about the problem here.

[goccy]

Thank you for your reports. Since it's the correct behavior for both to result in an error, I'll fix the behavior when there is only one element.

[jbutA]

Thanks for your extremely fast response!

If I may ask a question. I've seen examples of global tags applied to mapping nodes, but couldn't find any of local tags on mapping nodes in the yaml spec.

Does this being correct behaviour originate in the library or in the spec or somewhere else?

[goccy]

For example, the following tag is fine, but if an invalid tag is specified, it should result in an error.

mapping: !!map
  scalar1: 1

[goccy]

@jbutA I've fixed this problem with #526 and it merged into master branch.
Please confirm this ?

[jbutA]

The behaviour now is that no application-specific tags (!someTagName) are allowed in any context. Is that necessary at the parsing stage? User code that hooks into the syntax tree can have uses for the application-specific tags, right?

[jbutA]

But I can confirm that the behaviour is now consistent.

[goccy]

I've supported application-specific local tag with this PR ( #527 ).
These provided examples are processed valid yaml. Thank you !