refac(structure): remove leading gitea directory

The following pull request removes the `gitea` directory. With regard to
maintaining act_runners in a separate git repository or helm chart, this
additional directory becomes redundant.

templates/metrics-secret.yaml

@@ -0,0 +1,12 @@
+{{- if and (.Values.gitea.metrics.enabled) (.Values.gitea.metrics.serviceMonitor.enabled) (.Values.gitea.metrics.token) -}}
+apiVersion: v1
+kind: Secret
+metadata:
+  name: {{ include "gitea.metrics-secret-name" . }}
+  namespace: {{ .Values.namespace | default .Release.Namespace }}
+  labels:
+    {{- include "gitea.labels" . | nindent 4 }}
+type: Opaque
+data:
+  token: {{ .Values.gitea.metrics.token  | b64enc }}
+{{- end }}