refactor(http): Don't hardcode TLS configuration

- TLS 1.2 is used as MinVersion by default
- With regard to CipherSuites, in Go 1.22 RSA key exchange based cipher suites
  were removed from the default list, and in Go 1.23 3DES cipher suites were
  removed as well. Ciphers for TLS1.3 aren't configurable.
- No need to specify CurveP25, as the servers will likely disable the weird
  ones like CurveP384 and CurveP521. Removing the explicit specification also
  enables the post-quantum X25519MLKEM768, wow!

I trust the go team to make better choices on the long term than us keeping
miniflux up to date with the latest TLS trend.

internal/http/server/httpd.go

@@ -4,7 +4,6 @@
 package httpd // import "miniflux.app/v2/internal/http/server"
 
 import (
-	"crypto/tls"
 	"fmt"
 	"log/slog"
 	"net"
@@ -98,26 +97,6 @@ func startUnixSocketServer(server *http.Server, socketFile string) {
 	}(socketFile)
 }
 
-func tlsConfig() *tls.Config {
-	// See https://blog.cloudflare.com/exposing-go-on-the-internet/
-	// And https://wiki.mozilla.org/Security/Server_Side_TLS
-	return &tls.Config{
-		MinVersion: tls.VersionTLS12,
-		CurvePreferences: []tls.CurveID{
-			tls.CurveP256,
-			tls.X25519,
-		},
-		CipherSuites: []uint16{
-			tls.TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,
-			tls.TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,
-			tls.TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305,
-			tls.TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305,
-			tls.TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,
-			tls.TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,
-		},
-	}
-}
-
 func startAutoCertTLSServer(server *http.Server, certDomain string, store *storage.Storage) {
 	server.Addr = ":https"
 	certManager := autocert.Manager{
@@ -125,7 +104,6 @@ func startAutoCertTLSServer(server *http.Server, certDomain string, store *stora
 		Prompt:     autocert.AcceptTOS,
 		HostPolicy: autocert.HostWhitelist(certDomain),
 	}
-	server.TLSConfig = tlsConfig()
 	server.TLSConfig.GetCertificate = certManager.GetCertificate
 	server.TLSConfig.NextProtos = []string{"h2", "http/1.1", acme.ALPNProto}
 
@@ -148,7 +126,6 @@ func startAutoCertTLSServer(server *http.Server, certDomain string, store *stora
 }
 
 func startTLSServer(server *http.Server, certFile, keyFile string) {
-	server.TLSConfig = tlsConfig()
 	go func() {
 		slog.Info("Starting TLS server using a certificate",
 			slog.String("listen_address", server.Addr),