fix: Allow custom Git OAuth URLs (#4758)

Fixes an issue reported in Discord where custom endpoints
weren't working.

cli/deployment/config.go

@@ -462,7 +462,8 @@ func readSliceFromViper[T any](vip *viper.Viper, key string, value any) []T {
 			if prop == "-" {
 				prop = fve.Tag.Get("yaml")
 			}
-			value := vip.Get(fmt.Sprintf("%s.%d.%s", key, entry, prop))
+			configKey := fmt.Sprintf("%s.%d.%s", key, entry, prop)
+			value := vip.Get(configKey)
 			if value == nil {
 				continue
 			}
@@ -470,6 +471,11 @@ func readSliceFromViper[T any](vip *viper.Viper, key string, value any) []T {
 				newType := reflect.Indirect(reflect.New(elementType))
 				instance = &newType
 			}
+			switch instance.Field(i).Type().String() {
+			case "[]string":
+				value = vip.GetStringSlice(configKey)
+			default:
+			}
 			instance.Field(i).Set(reflect.ValueOf(value))
 		}
 		if instance == nil {

cli/deployment/config_test.go

@@ -158,6 +158,7 @@ func TestConfig(t *testing.T) {
 			"CODER_GITAUTH_0_AUTH_URL":      "https://auth.com",
 			"CODER_GITAUTH_0_TOKEN_URL":     "https://token.com",
 			"CODER_GITAUTH_0_REGEX":         "github.com",
+			"CODER_GITAUTH_0_SCOPES":        "read write",
 
 			"CODER_GITAUTH_1_ID":            "another",
 			"CODER_GITAUTH_1_TYPE":          "gitlab",
@@ -177,6 +178,7 @@ func TestConfig(t *testing.T) {
 				AuthURL:      "https://auth.com",
 				TokenURL:     "https://token.com",
 				Regex:        "github.com",
+				Scopes:       []string{"read", "write"},
 			}, {
 				ID:           "another",
 				Type:         "gitlab",