[bitnami/common] Sanitize truncated chart label values

[pschiffe]

Description of the change

This updates the bitnami/common label helpers so generated Kubernetes label values remain valid after SemVer build metadata is normalized and truncated.

Specifically:

• Adds a shared common.labels.value helper.
• Applies it to helm.sh/chart.
• Applies it to app.kubernetes.io/version.
• Preserves the existing + to _ conversion and 63-character truncation.
• Trims trailing non-alphanumeric characters after truncation.

This prevents labels such as helm.sh/chart from ending in _ when a long chart version with build metadata is truncated.

Benefits

Charts can use long SemVer versions containing build metadata without rendering Kubernetes-invalid labels.

Example fixed case:

  grid-checkout-internal-gateway@2.1.13-SNAPSHOT-20260126-095732+ba14b1c07afe

Previously this could truncate to a label ending in _, which Kubernetes rejects. The helper now trims that trailing invalid character while preserving the valid prefix.

Possible drawbacks

If a generated helm.sh/chart or app.kubernetes.io/version label would previously have ended with a non-alphanumeric character after truncation, the rendered label value is now slightly shorter. The chart version and appVersion themselves are unchanged.

Applicable issues

• fixes common.names.chart not DNS conform in special case (63 chars + _) #36452

Additional information

Validation performed:

• Rendered a temporary consumer chart using a long chart version with build metadata.
• Verified rendered helm.sh/chart and app.kubernetes.io/version labels:
  • are no longer than 63 characters
  • match Kubernetes label value syntax
  • end with an alphanumeric character
• Ran:

  helm lint bitnami/common

Checklist

• Chart version bumped in Chart.yaml according to semver. This is not necessary when the changes only affect README.md files.
• Variables are documented in the values.yaml and added to the README.md using readme-generator-for-helm
• Title of the pull request follows this pattern [bitnami/<name_of_the_chart>] Descriptive title
• All commits signed off and in agreement of Developer Certificate of Origin (DCO)

[dgomezleon]

LGTM! Thanks for contributing