chore: untrack and gitignore keyvault-secret-provider.local.yaml

The file holds per-cluster Azure tenant/identity/Key Vault metadata —
copied from keyvault-secret-provider.yaml (the tracked template) and
edited locally per cluster. It got committed by accident; remove from
the index but keep on disk, and add an explicit pattern under the
charts/ section that actually matches its real location (the previous
*/keyvault-secret-provider.local.yaml only matched one directory level).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: cosmic-flood

.gitignore

@@ -206,4 +206,5 @@ data-process/stats-service/.env
 # ======
 # charts/ (Helm)
 # ======
-charts/featbit-rda/**/values.local.yaml
+charts/featbit-rda/**/values.local.yaml
+charts/featbit-rda/**/keyvault-secret-provider.local.yaml