fix: remove unused cli flags

The `--internal` and `--unstable` cli flags were never actually used by
openapi-generator. This commit removes no functionality of the tool,
it only cleans the cli interface.

Ticket: VL-1855

packages/openapi-generator/src/cli.ts

@@ -53,20 +53,6 @@ const app = command({
       long: 'description',
       short: 'd',
     }),
-    includeInternal: flag({
-      type: boolean,
-      description: 'include routes marked private',
-      long: 'internal',
-      short: 'i',
-      defaultValue: () => false,
-    }),
-    includeUnstable: flag({
-      type: boolean,
-      description: 'include routes marked unstable',
-      long: 'unstable',
-      short: 'u',
-      defaultValue: () => false,
-    }),
     codecFile: option({
       type: optional(string),
       description: 'Custom codec definition file',