CI - replace test data caching with git clone fetch-depth 1

.github/workflows/ci.yml

@@ -62,25 +62,13 @@ jobs:
       - name: Check out pipeline code
         uses: actions/checkout@v3
 
-      - name: Hash Github Workspace
-        id: hash_workspace
-        run: |
-          echo "digest=$(echo ampliseq_2.6_${{ github.workspace }} | md5sum | cut -c 1-25)" >> $GITHUB_OUTPUT
-
-      - name: Cache test data
-        id: cache-testdata
-        uses: actions/cache@v3
-        with:
-          path: test-datasets/
-          key: ${{ steps.hash_workspace.outputs.digest }}
-
       - name: Check out test data
-        if: steps.cache-testdata.outputs.cache-hit != 'true'
         uses: actions/checkout@v3
         with:
           repository: nf-core/test-datasets
           ref: ampliseq
           path: test-datasets/
+          fetch-depth: 1
 
       - name: Replace remote paths in samplesheets
         run: |