Release workflow: Use Python package version instead of manual input

CMK-18197

.github/workflows/release.yaml

@@ -3,15 +3,7 @@
 
 ---
   name: "Release"
-  on:
-    workflow_dispatch:
-      inputs:
-        tag:
-          description: >
-            Tag set by this GitHub workflow.
-            Should follow SemVer and is not allowed to exist already.
-          required: true
-          type: string
+  on: workflow_dispatch
 
   jobs:
     tests:
@@ -35,13 +27,19 @@
         - run: poetry build
 
         - run: tar --create --gzip --verbose --file dist.tar.gz dist
+
+        - name: "Set release according to package version"
+          id: compute-tag
+          run: |
+            version="$(poetry version | cut --delimiter " " --fields 2)"
+            echo "TAG=v${version}" >> "${GITHUB_OUTPUT}"
   
         - name: "Push release tag"
           # This is publicly visible and needs to be manually fixed if any
           # consecutive step fails.
           run: |
-            git tag ${{ inputs.tag }}  # Fails, if tag exists.
-            git push origin ${{ inputs.tag }}
+            git tag ${{ steps.compute-tag.outputs.TAG }} # Fails, if tag exists.
+            git push origin ${{ steps.compute-tag.outputs.TAG }}
   
         - uses: ncipollo/[email protected]
           with:
@@ -55,6 +53,6 @@
             artifactErrorsFailBuild: true
             updateOnlyUnreleased: true
             makeLatest: false
-            tag: ${{ inputs.tag }}
+            tag: ${{ steps.compute-tag.outputs.TAG }}
 
         - uses: pypa/gh-action-pypi-publish@release/v1