refactor: switch config format from YAML to TOML

- Replace gopkg.in/yaml.v3 with github.com/BurntSushi/toml
- Update struct tags from yaml to toml
- Update config tests to use TOML syntax
- Add testdata/config.toml, update Helm configmap template

deploy/helm/proto-gen/templates/configmap.yaml

@@ -3,22 +3,26 @@ kind: ConfigMap
 metadata:
   name: {{ .Release.Name }}-config
 data:
-  config.yaml: |
-    server:
-      addr: ":8080"
-    git:
-      type: gitea
-      base_url: "{{ .Values.git.baseUrl }}"
-      token: "${GIT_TOKEN}"
-    cluster:
-      kubeconfig: /etc/proto-gen/kubeconfig
-      namespace: {{ .Values.cluster.namespace }}
-      job_timeout: {{ .Values.cluster.jobTimeout }}
-      max_concurrent: {{ .Values.cluster.maxConcurrent }}
-    toolchain_registry: "{{ .Values.toolchainRegistry }}"
-    target_repo_template: "{{ .Values.targetRepoTemplate }}"
-    plugins:
-      {{- range .Values.plugins }}
-      - language: {{ .language }}
-        image: "{{ .image }}"
-      {{- end }}
+  config.toml: |
+    [server]
+    addr = ":8080"
+
+    [git]
+    type = "gitea"
+    base_url = "{{ .Values.git.baseUrl }}"
+    token = "${GIT_TOKEN}"
+
+    [cluster]
+    kubeconfig = "/etc/proto-gen/kubeconfig"
+    namespace = "{{ .Values.cluster.namespace }}"
+    job_timeout = {{ .Values.cluster.jobTimeout }}
+    max_concurrent = {{ .Values.cluster.maxConcurrent }}
+
+    toolchain_registry = "{{ .Values.toolchainRegistry }}"
+    target_repo_template = "{{ .Values.targetRepoTemplate }}"
+
+    {{- range .Values.plugins }}
+    [[plugins]]
+    language = "{{ .language }}"
+    image = "{{ .image }}"
+    {{- end }}