[DEVOPS] Free text allowed for version when releasing helm

## Problem

Currently, the **Helm release** process is completely manual and decoupled from the main application release.

After building and releasing a new version of the application, anyone can enter **any version number** freely when triggering a Helm release. This makes it very easy to:
- Use a version that doesn't match the actual application release
- Introduce typos or incorrect versions
- Cause a mismatch between the application version and the Helm chart version

These inconsistencies lead to deployment confusion, troubleshooting difficulties, and potential production issues.

## Expected Behavior

The Helm release dispatch workflow should be improved to ensure the Helm chart version always stays **in sync** with the application release.

### Proposed Solution:
- When triggering a Helm release, instead of a free-text input field, provide a **dropdown list** containing all available versions from the existing releases.
- Users should only be able to select a version that has already been successfully released.
- The selected version should be automatically used as the Helm chart version.

This change will eliminate manual errors and guarantee that the Helm version remains perfectly synchronized with the application version.

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### Acceptance Criteria

- [ ] Helm release workflow replaces the free-text version input with a dropdown
- [ ] Dropdown shows only versions that exist in the official releases
- [ ] Selected version is automatically applied to the Helm chart
- [ ] It is no longer possible to enter an arbitrary or non-existent version
- [ ] Clear error message is shown if no releases are available

Start at the Helm release dispatch workflow and inspect how it currently accepts the version and how official releases are exposed. The work is done when the workflow offers only successfully released versions, applies the selected version to the Helm chart, rejects arbitrary input, and reports when no releases are available.

Written by the indexing model from the issue text.