Remove blanket suppression for compact source file test inputs once all checks support compact source files

Remove blanket suppression for compact source file test inputs once all checks support compact source files

### Context

To support JEP 512 (Compact Source Files and instance `main`), the grammar now parses compact source files into a `COMPACT_COMPILATION_UNIT` root (see checkstyle/checkstyle#17810). Individual checks are being made compact-aware one by one. Until that work is complete, many checks either throw (for example, `RequireThis` NPEs when there is no class frame for the implicit unnamed class) or raise false positives on compact-source test inputs. To avoid adding scattered per-file suppressions for every new compact input, we are adding a single blanket suppression covering all compact-source test inputs:

`**/resources-noncompilable/**/Input*CompactSourceFile*.java`

### Location to remove

The suppression to remove lives in:

https://github.com/checkstyle/contribution/blob/35866f4580eaa0abc0afb1d5363582a45f634dd1/checkstyle-tester/projects-to-test-on.properties#L55-L56

### Task

This is a tracking issue to remove that blanket suppression once every check supports compact source files, so we do not leave a permanent blanket exclusion in place.

Parent tracker: checkstyle/checkstyle#19971 (Java 25 compact source files and instance main).