try to use expr for inputs validation

Author: baev

.github/workflows/release.yml

@@ -16,11 +16,11 @@ jobs:
     steps:
       - name: "Check release version"
         run: |
-          [ "${{ github.event.inputs.releaseVersion }}" '=~' '^[0-9]+\.[0-9]+\.[0-9]+$' ]
+          expr "${{ github.event.inputs.releaseVersion }}" : '[[:digit:]][[:digit:]]*\.[[:digit:]][[:digit:]]*\.[[:digit:]][[:digit:]]*$'
 
       - name: "Check next version"
         run: |
-          [ "${{ github.event.inputs.nextVersion }}" '=~' '^[0-9]+\.[0-9]+$' ]
+          expr "${{ github.event.inputs.nextVersion }}" : '[[:digit:]][[:digit:]]*\.[[:digit:]][[:digit:]]*$'
 
       - uses: actions/checkout@v2.3.4
         with: