Revert "Re-attempt to increment cache number"

This reverts commit 9ee8243.

Author: ArchiePayne

.github/actions/vtk-install-dep/action.yml

@@ -26,10 +26,10 @@ runs:
 
     - name: Cache VTK
       id: cache-vtk
-      uses: actions/cache/restore@v5
+      uses: actions/cache/restore@v4
       with:
         path: dependencies/vtk_install
-        key: vtk-${{ inputs.vtk_version }}${{ inputs.openvdb_version != '' && format('-openvdb-{0}', inputs.openvdb_version) || '' }}-${{runner.os}}-${{inputs.raytracing_label}}-${{inputs.cpu}}-1
+        key: vtk-${{ inputs.vtk_version }}${{ inputs.openvdb_version != '' && format('-openvdb-{0}', inputs.openvdb_version) || '' }}-${{runner.os}}-${{inputs.raytracing_label}}-${{inputs.cpu}}-2
 
     - name: Setup VTK
       if: steps.cache-vtk.outputs.cache-hit != 'true'