fix CI workflow for archdetect GPU by replacing s/__EESSI_VERSION_DEFAULT__/ placeholder in init/eessi_defaults

Author: boegel

.github/workflows/tests_archdetect_nvidia_gpu.yml

@@ -17,6 +17,9 @@ jobs:
           - 2xa100 # cc80, supported with (atleast) zen2 CPU
           - 4xa100 # cc80, supported with (atleast) zen2 CPU
           - cc01 # non-existing GPU
+        EESSI_VERSION:
+          - '2023.06'
+          - '2025.06'
       fail-fast: false
     steps:
     - name: checkout
@@ -31,6 +34,10 @@ jobs:
           cvmfs_http_proxy: DIRECT
           cvmfs_repositories: software.eessi.io
 
+    - name: Fix EESSI version in init scripts
+      run: |
+        sed -i "s/__EESSI_VERSION_DEFAULT__/${{matrix.EESSI_VERSION}}/g" init/eessi_defaults
+
     - name: test accelerator detection
       run: |
           export EESSI_SOFTWARE_SUBDIR_OVERRIDE='x86_64/amd/zen2'