Make the "is this a Hugo Module" logic more lenient

Now we only try to load modules via Go if there is one or more modules imported in project config.

Fixes #6299

modules/client.go

@@ -279,12 +279,12 @@ func (c *Client) Init(path string) error {
 	return nil
 }
 
-func (c *Client) isProbablyModule(path string) bool {
+func isProbablyModule(path string) bool {
 	return module.CheckPath(path) == nil
 }
 
 func (c *Client) listGoMods() (goModules, error) {
-	if c.GoModulesFilename == "" {
+	if c.GoModulesFilename == "" || !c.moduleConfig.hasModuleImport() {
 		return nil, nil
 	}