fix(config): normalize migrated package rule matchers

[jonathanmorley]

Changes

This addresses #43936.

In summary, the current matcher normalization causes some configurations to fail when evaluated against the recently tightened matcher validations.
This changes the normalization of matchers to comply with the new requirements.

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[RahulGautamSingh]

Nice fix on the core bug, but I think the normalization pass is over-scoped.

The real defect is narrow:

The old migration wrapped match-all patterns as regexes (/*/, !/*/), and validation rejects those because they fail to compile.

The two-line fix in migratePattern / migrateExcludePattern (emit * and !** instead) resolves that completely, since both are globs and skip the regex check.

Everything in normalizeRegexOrGlobMatchers / normalizeMatchers and the supporting Sets and predicates only collapses combinations that already pass validation:

['*', '!/foo/'] to ['!/foo/']
['**', 'foo'] to ['**']
['!**', 'foo'] to ['!**']

None of those trigger a validation error, so none of it is needed to fix the reported issue.

[jonathanmorley]

I think there are two migration failures at play here, that are potentially getting conflated:

1. Legacy match-all patterns can become invalid regex tokens, such as "*" becoming "/*/". The migratePattern / migrateExcludePattern changes fix this by emitting "*" and "!**".
2. Migration can produce individually valid matchers that form an invalid array. The original reproduction is:

{
  "packagePatterns": ["*"],
  "excludePackagePatterns": ["some-package"]
}

Without normalization, that becomes:

{
  "matchPackageNames": ["*", "!/some-package/"]
}

regex-glob-matchers.ts rejects this because it contains * alongside another matcher.

[RahulGautamSingh]

Can we fix this by adding a helper function which after migration checks the failing case ie. that * pattern is not combined with others?

The current solution looks very bloated to me, and I don;t want it to be a maintenance issue in future.