Prior to this commit, the URL handler mapping would expose the matching
pattern, the path within mapping and matching URI variables as request
attributes. This was the case when the mapping would use the
`AntPathMatcher` as matching infrastructure, but not when using the
`PathPattern` variant. In this case, the map of URI variables would be
`null`. This could throw `IllegalArgumentException` when `RedirectView`
instances were relying on the presence of specific variables.
This commit ensures that URI variables are also extracted when the
`PathPatternParser` is used.
Fixes gh-33422
6a20987933