[CHORE]: Fix CI rust env and apply same corrections to `pii_filter` plugin

[lucarlig]

Description:

Current CI there is duplication (see context in PR #2785 comment: #2785 (comment)).

Issues:

• duplicated testing

Tasks:

• Enable Rust env in main pytest CI, and make sure the parameterized rust test are never ignored in pytest CI (enforce it)
• Remove the original pytest specialized / separate CI for Rust plugins (and related Rust env setup in main pytest)
• for PII_filter merge the test with rust in the name with the python plugin tests to one parameterized test suite (integration, unit, differential),
• Refactor tests to use parameterized approach with use_rust flag (run both Python and Rust implementations from main pytest; skip Rust-specific cases when inapplicable), parameterization can skip internal unit tests function not present in rust
• Ensure both plugins pass CI (unit tests + lint + type check) in the new architecture
• Verify no breaking changes in behavior
• Remove develop dependency from test-python Makefile target to prevent duplicate Rust test execution in python-integration CI job

Acceptance criteria:

• CI run parameterized tests (rust/python)
• pii_filter special tests are merged and conformed with python tests
• No new test failures introduced
• Separate Rust-only pytest CI removed; all tests consolidated under main pytest with parameterization

Additional context
Reference comment: #2785 (comment)