oauth2-client: migrate apps to use oauth2-client helm chart (#90)

* headscale: use oauth2-client helm chart

* pihole: use oauth2-client helm chart

* matrix: use oauth2-client helm chart

* oauth2: pass issuer address to pihole, headscale and matrix apps

* pihole: fix secret name

* matrix: fix version to v1.98.0

* headscale: make oauth2-client depend on auth release

---------

Co-authored-by: Giorgi Lekveishvili <lekva@gl-mbp-m1-max.local>
diff --git a/charts/pihole/templates/oauth2-proxy-config.yaml b/charts/pihole/templates/oauth2-proxy-config.yaml
index 2141bce..5aebbb0 100644
--- a/charts/pihole/templates/oauth2-proxy-config.yaml
+++ b/charts/pihole/templates/oauth2-proxy-config.yaml
@@ -9,7 +9,7 @@
     apiVersion: v1
     kind: ConfigMap
     metadata:
-      name: {{ .Values.oauth2.configName }}
+      name: {{ .Values.configName }}
       namespace: {{ .Release.Namespace }}
     data:
       oauth2-proxy.cfg: |
@@ -53,6 +53,6 @@
         cookie_httponly = true
 
         provider = "oidc"
-        oidc_issuer_url = "{{ .Values.hydraPublic }}"
+        oidc_issuer_url = "{{ .Values.oauth2.issuer }}"
         provider_display_name = "PCloud"
         profile_url = "{{ .Values.profileUrl }}"