fix: Use file-names-only snapshots for RSEM and HISAT2 indices

Apply the same non-deterministic snapshot fix to rsem_index and
hisat2_index that was applied to star_index, salmon_index, and
kallisto_index. RSEM indices contain STAR files (including Log.out)
which have non-deterministic content.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: pinin4fjords

CHANGELOG.md

@@ -23,7 +23,7 @@ Special thanks to the following for their contributions to the release:
 - [PR #1669](https://github.com/nf-core/rnaseq/pull/1669) - Enable SeqKit stats MultiQC module for RiboDetector rRNA removal
 - [PR #1672](https://github.com/nf-core/rnaseq/pull/1672) - Document star_rsem STAR aligner settings and customization
 - [PR #1677](https://github.com/nf-core/rnaseq/pull/1677) - Apply Nextflow 25 strict syntax fixes
-- [PR #1687](https://github.com/nf-core/rnaseq/pull/1687) - Fix PREPARE_GENOME tests: use single aligner values, correct aligner assignments for index-specific tests, add Kallisto test, remove ineffective Sentieon tests, fix non-deterministic index snapshots
+- [PR #1687](https://github.com/nf-core/rnaseq/pull/1687) - Fix PREPARE_GENOME tests: use single aligner values, correct aligner assignments for index-specific tests, add Kallisto test, remove ineffective Sentieon tests, use file-names-only snapshots for all non-deterministic indices (STAR, Salmon, Kallisto, RSEM, HISAT2)
 
 ### Parameters