[Finder] Fixed AbstractFindAdapter for non-realpaths (eg. Phar archives)

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #7035
| License       | MIT

Fixes default Adapter chain handling if we search in Phar archives.