refactor: serve the api specs as plain json (#38715)

The api specs were Go templates whose committed form was not a valid
swagger document, so `swagger-validate`, `generate-openapi.go` and
`.spectral.yaml` each worked around it. They are now plain json,
substituted at serve time.

Renaming them off `.tmpl` also stops `make fmt` rewriting them, which
used to bump their mtime and silently skip the next `make
generate-swagger`.

Also enables stricter spectral linting: extends `lint-swagger` to the
OpenAPI 3 spec, turns on `openapi-tags`, `operation-singular-tag` and
`operation-tag-defined`, adds a top-level `tags` array with descriptions
to the swagger input, and drops the redundant `repository` tag from
`POST /user/repos`.

---------

Signed-off-by: silverwind <me@silverwind.io>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>
Co-authored-by: Giteabot <teabot@gitea.io>

templates/swagger/v1-input.json

@@ -0,0 +1,17 @@
+{
+  "info": {
+    "version": "0.0.0+GITEA-API-APP-VERSION"
+  },
+  "basePath": "/GITEA-API-APP-SUBURL/api/v1",
+  "tags": [
+    {"name": "admin", "description": "Site administration"},
+    {"name": "issue", "description": "Issues, pull requests, comments, labels and milestones"},
+    {"name": "miscellaneous", "description": "Miscellaneous endpoints"},
+    {"name": "notification", "description": "User notifications"},
+    {"name": "organization", "description": "Organizations and teams"},
+    {"name": "package", "description": "Package registry"},
+    {"name": "repository", "description": "Repositories and their contents"},
+    {"name": "settings", "description": "Server settings"},
+    {"name": "user", "description": "The authenticated user"}
+  ]
+}

templates/swagger/v1-openapi3.generated.json

@@ -10733,7 +10733,7 @@
       "url": "http://opensource.org/licenses/MIT"
     },
     "title": "Gitea API",
-    "version": "{{.SwaggerAppVer}}"
+    "version": "0.0.0+GITEA-API-APP-VERSION"
   },
   "openapi": "3.0.3",
   "paths": {
@@ -33073,7 +33073,6 @@
         },
         "summary": "Create a repository",
         "tags": [
-          "repository",
           "user"
         ]
       }
@@ -34201,7 +34200,45 @@
   ],
   "servers": [
     {
-      "url": "{{.SwaggerAppSubUrl}}/api/v1"
+      "url": "/GITEA-API-APP-SUBURL/api/v1"
+    }
+  ],
+  "tags": [
+    {
+      "description": "Site administration",
+      "name": "admin"
+    },
+    {
+      "description": "Issues, pull requests, comments, labels and milestones",
+      "name": "issue"
+    },
+    {
+      "description": "Miscellaneous endpoints",
+      "name": "miscellaneous"
+    },
+    {
+      "description": "User notifications",
+      "name": "notification"
+    },
+    {
+      "description": "Organizations and teams",
+      "name": "organization"
+    },
+    {
+      "description": "Package registry",
+      "name": "package"
+    },
+    {
+      "description": "Repositories and their contents",
+      "name": "repository"
+    },
+    {
+      "description": "Server settings",
+      "name": "settings"
+    },
+    {
+      "description": "The authenticated user",
+      "name": "user"
     }
   ]
 }

templates/swagger/v1-swagger.generated.json

@@ -17,9 +17,9 @@
       "name": "MIT",
       "url": "http://opensource.org/licenses/MIT"
     },
-    "version": "{{.SwaggerAppVer}}"
+    "version": "0.0.0+GITEA-API-APP-VERSION"
   },
-  "basePath": "{{.SwaggerAppSubUrl}}/api/v1",
+  "basePath": "/GITEA-API-APP-SUBURL/api/v1",
   "paths": {
     "/admin/actions/jobs": {
       "get": {
@@ -20912,7 +20912,6 @@
           "application/json"
         ],
         "tags": [
-          "repository",
           "user"
         ],
         "summary": "Create a repository",
@@ -32087,5 +32086,43 @@
     {
       "TOTPHeader": []
     }
+  ],
+  "tags": [
+    {
+      "description": "Site administration",
+      "name": "admin"
+    },
+    {
+      "description": "Issues, pull requests, comments, labels and milestones",
+      "name": "issue"
+    },
+    {
+      "description": "Miscellaneous endpoints",
+      "name": "miscellaneous"
+    },
+    {
+      "description": "User notifications",
+      "name": "notification"
+    },
+    {
+      "description": "Organizations and teams",
+      "name": "organization"
+    },
+    {
+      "description": "Package registry",
+      "name": "package"
+    },
+    {
+      "description": "Repositories and their contents",
+      "name": "repository"
+    },
+    {
+      "description": "Server settings",
+      "name": "settings"
+    },
+    {
+      "description": "The authenticated user",
+      "name": "user"
+    }
   ]
 }

templates/swagger/v1_input.json

@@ -1,6 +0,0 @@
-{
-  "info": {
-    "version": "{{.SwaggerAppVer}}"
-  },
-  "basePath": "{{.SwaggerAppSubUrl}}/api/v1"
-}