Fix src/openapi/v7.* like MTC-30388 to avoid build error

Author: masiuchi

src/openapi/v7.json

@@ -17366,7 +17366,7 @@
                     "type": "string"
                   },
                   "theme_name": {
-                    "description": "If not specified, the default value is dynamically generated as 'Theme from <SiteName>', where <SiteName> represents the name of the site.",
+                    "description": "If not specified, the default value is dynamically generated as 'Theme from (SiteName)', where (SiteName) represents the name of the site.",
                     "type": "string"
                   },
                   "theme_version": {

src/openapi/v7.yaml

@@ -12252,7 +12252,7 @@ paths:
                   description: 'Can only contain letters (a-z, A-Z), numbers (0-9), dashes (-), and underscores (_). Must start with a letter.'
                   type: string
                 theme_name:
-                  description: "If not specified, the default value is dynamically generated as 'Theme from <SiteName>', where <SiteName> represents the name of the site."
+                  description: "If not specified, the default value is dynamically generated as 'Theme from (SiteName)', where (SiteName) represents the name of the site."
                   type: string
                 theme_version:
                   default: 1.0