Many rpm tests are not running under bazel 7 (bzlmod)

Now that bazel 7 is the default for CI, and we are using bzlmod, the toolchain finder does not work. Worse than failing, they just silently skip, so it's as good as not having the tests.

```
//tests/rpm:analysis_tests_conflicting_inputs_base_case_passes_analysis SKIPPED
//tests/rpm:analysis_tests_conflicting_inputs_conflict_with_dir SKIPPED
//tests/rpm:analysis_tests_conflicting_inputs_conflict_with_file SKIPPED
//tests/rpm:analysis_tests_conflicting_inputs_conflict_with_symlink SKIPPED
//tests/rpm:analysis_tests_naming_no_extra SKIPPED
//tests/rpm:analysis_tests_naming_with_different_name SKIPPED
//tests/rpm:pkg_rpm_basic_test SKIPPED
//tests/rpm:pkg_rpm_smoke SKIPPED
//tests/rpm:test_golden_sub_rpm_contents SKIPPED
//tests/rpm:test_rpm_dirs_contents_golden_test SKIPPED
//tests/rpm/source_date_epoch:source_date_epoch_from_file SKIPPED
//tests/rpm/source_date_epoch:source_date_epoch_insource SKIPPED
//tests/rpm/tree_artifacts:layer_with_files SKIPPED
//tests/rpm/tree_artifacts:layer_with_files_reversed SKIPPED
//tests/rpm/tree_artifacts:treeartifact_ops SKIPPED
```