Do not remove the 'v' prefix from chart versions (#821)

* Change format of non-release chart versions

Our non-release chart versions were using semver pre-release format
(version appended by a hyphen and an identifier). This commit changes
the format by appending build metadata, which uses a plus instead of
a hyphen.

The benefit of this change is that pre-release version identifiers must
not include leading zeros, whereas build metadata can contain any ASCII
alphanumerics and hyphens without further restrictions.

Since we append a short git commit sha to the semver version, we can't
rule out that the sha might start with a zero.

* Do not remove the 'v' prefix from chart versions

Our other artifacts, such as container images, all use the 'v' prefix
for their versions. Keeping the prefix for the chart versions as well
ensures taht our versioning scheme is consistent.

Author: gonzolino

.github/workflows/release-chart.yaml

@@ -43,13 +43,13 @@ jobs:
         run: |
           if [[ "${{ github.event_name }}" == "push" && "${{ github.ref }}" == "refs/heads/main" ]]; then
             # Use SHA for main branch
-            CHART_VERSION="0.0.0-$(echo ${{ github.sha }} | cut -c1-7)"
+            CHART_VERSION="v0.0.0+$(echo ${{ github.sha }} | cut -c1-7)"
           elif [[ "${{ github.event_name }}" == "push" && "${{ github.ref }}" =~ ^refs/tags/v[0-9]+\.[0-9]+\.[0-9]+$ ]]; then
-            # Use tag version (strip 'v' prefix)
-            CHART_VERSION="${GITHUB_REF#refs/tags/v}"
+            # Use tag version
+            CHART_VERSION="${GITHUB_REF_NAME}"
           else
             # Use PR SHA for dry run
-            CHART_VERSION="0.0.0-$(echo ${{ github.sha }} | cut -c1-7)"
+            CHART_VERSION="v0.0.0+$(echo ${{ github.sha }} | cut -c1-7)"
           fi
           echo "version=$CHART_VERSION" >> $GITHUB_OUTPUT
 
@@ -67,4 +67,4 @@ jobs:
         run: |
           helm push gardener-extension-provider-ironcore-${{ steps.chart_version.outputs.version }}.tgz oci://ghcr.io/${{ github.repository_owner }}/charts
           helm push gardener-extension-admission-ironcore-runtime-${{ steps.chart_version.outputs.version }}.tgz oci://ghcr.io/${{ github.repository_owner }}/charts
-          helm push gardener-extension-admission-ironcore-application-${{ steps.chart_version.outputs.version }}.tgz oci://ghcr.io/${{ github.repository_owner }}/charts
+          helm push gardener-extension-admission-ironcore-application-${{ steps.chart_version.outputs.version }}.tgz oci://ghcr.io/${{ github.repository_owner }}/charts