[core] Fix false multiple decorator error when combining schema.output and tag

[ArnavBalyan]

Changes

• SchemaOutput inherits from tag and shares its lifecycle name, so multiplicity check tripped on the existing tag instance.
• Count only decorators of the same concrete class as self before raising, independent decorators sharing a lifecycle name now compose.

How I tested this

• UT

Notes

Checklist

• PR has an informative and human-readable title (this will be pulled into the release notes)
• Changes are limited to a single goal (no scope creep)
• Code passed the pre-commit check & code is left cleaner/nicer than when first encountered.
• Any change in functionality is tested
• New functions are documented (with a description, list of inputs, and expected output)
• Placeholder code is flagged / future TODOs are captured in comments
• Project documentation has been updated if adding/changing functionality.

[skrawcz]

Looks good -- mind fixing the precommit, ruff needs to run:

ruff format..............................................................Failed
- hook id: ruff-format
- files were modified by this hook

  1 file reformatted, 1003 files left unchanged
  warning: The top-level linter settings are deprecated in favour of their counterparts in the `lint` section. Please update the following options in `ui/sdk/ruff.toml`:
    - 'per-file-ignores' -> 'lint.per-file-ignores'

[ArnavBalyan]

Hey @skrawcz this is fixed under #1572

[ArnavBalyan]

Thanks @skrawcz !