modernize the codebase

Run the modernize linter across the codebase.
Change generated by running:

```
go run golang.org/x/tools/gopls/internal/analysis/modernize/cmd/modernize@latest -fix -test ./...
```

Ref:
https://pkg.go.dev/golang.org/x/tools/gopls/internal/analysis/modernize

internal/web/handlers/oauth.go

@@ -10,9 +10,9 @@ import (
 )
 
 type OauthLoginHandler struct {
-	jwt         *auth.JwtTokenGenerator
+	jwt          *auth.JwtTokenGenerator
 	oauthHandler *auth.GiteaOAuth2Handler
-	cfg         *config.Config
+	cfg          *config.Config
 }
 
 func NewOauthLoginHandler(
@@ -55,7 +55,7 @@ func (olh *OauthLoginHandler) LoginWithGitea(c *gin.Context) {
 	// Check if the user's email is in the allowed list
 	for _, email := range olh.cfg.GiteaOauthAllowedEmails {
 		if email == userEmail {
-			token, err := olh.jwt.GenerateToken(map[string]interface{}{"role": "admin"})
+			token, err := olh.jwt.GenerateToken(map[string]any{"role": "admin"})
 			if err != nil {
 				c.JSON(http.StatusInternalServerError, gin.H{"error": "Token generation failed"})
 				return
@@ -70,4 +70,4 @@ func (olh *OauthLoginHandler) LoginWithGitea(c *gin.Context) {
 	c.JSON(401, gin.H{
 		"error": "oauth login failed or your email does not have access",
 	})
-}
+}