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/matrix/templates/config-to-merge.yaml b/charts/matrix/templates/config-to-merge.yaml
index c34a2c7..eefe3e3 100644
--- a/charts/matrix/templates/config-to-merge.yaml
+++ b/charts/matrix/templates/config-to-merge.yaml
@@ -33,7 +33,7 @@
           - idp_id: pcloud
             idp_name: "PCloud"
             skip_verification: true
-            issuer: {{ .Values.oauth2.hydraPublic }}
+            issuer: {{ .Values.oauth2.issuer }}
             client_id: "{{`{{ .client_id }}`}}"
             client_secret: "{{`{{ .client_secret }}`}}"
             scopes: ["openid", "profile"]