build: go 1.24

We were running behind and there were quite some deprecations to update.
This was mostly in the upstream copy/pasta package but seems quite
minimal.

vendor/github.com/grpc-ecosystem/grpc-gateway/v2/runtime/mux.go

@@ -71,6 +71,7 @@ type ServeMux struct {
 	routingErrorHandler       RoutingErrorHandlerFunc
 	disablePathLengthFallback bool
 	unescapingMode            UnescapingMode
+	writeContentLength        bool
 }
 
 // ServeMuxOption is an option that can be given to a ServeMux on construction.
@@ -258,6 +259,13 @@ func WithDisablePathLengthFallback() ServeMuxOption {
 	}
 }
 
+// WithWriteContentLength returns a ServeMuxOption to enable writing content length on non-streaming responses
+func WithWriteContentLength() ServeMuxOption {
+	return func(serveMux *ServeMux) {
+		serveMux.writeContentLength = true
+	}
+}
+
 // WithHealthEndpointAt returns a ServeMuxOption that will add an endpoint to the created ServeMux at the path specified by endpointPath.
 // When called the handler will forward the request to the upstream grpc service health check (defined in the
 // gRPC Health Checking Protocol).