Remove unused music-assistant-skill chart

The chart is no longer needed. Removes the chart directory, its publish
workflow, and its row in the README chart table. Already published
versions remain in the registry.

Fixes #7

README.md

@@ -12,7 +12,6 @@ Collection of some self-made helm-charts. Each top-level directory is a standalo
 | `gotenberg` | Gotenberg | Deployment + Service only (no ingress) |
 | `homeassistant` | Home Assistant | StatefulSet, has `NOTES.txt` and Helm tests |
 | `matrix-synapse` | Matrix Synapse | StatefulSet plus an nginx delegation Deployment/Service |
-| `music-assistant-skill` | Music Assistant Alexa Skill | Uses `_helpers.tpl` (unlike the other charts) |
 | `outline` | Outline | StatefulSet, separate DB/Redis secrets |
 | `paperless-ngx` | Paperless-ngx | Largest chart: consume CronJob, SMB-connector PV/PVC, pre/post-consumption scripts ConfigMap |
 | `patchmon` | PatchMon | Two Deployments (frontend + backend), OIDC secret |