chore(deps-dev): bump @types/koa from 2.0.49 to 2.0.50

Bumps [@types/koa](https://github.com/DefinitelyTyped/DefinitelyTyped/tree/HEAD/types/koa) from 2.0.49 to 2.0.50.
- [Release notes](https://github.com/DefinitelyTyped/DefinitelyTyped/releases)
- [Commits](https://github.com/DefinitelyTyped/DefinitelyTyped/commits/HEAD/types/koa)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

package.json

@@ -36,7 +36,7 @@
   "devDependencies": {
     "@types/cheerio": "0.22.13",
     "@types/got": "9.6.7",
-    "@types/koa": "2.0.49",
+    "@types/koa": "2.0.50",
     "@vuepress/plugin-back-to-top": "1.1.0",
     "@vuepress/plugin-google-analytics": "1.1.0",
     "@vuepress/plugin-pwa": "1.1.0",

yarn.lock

@@ -1137,10 +1137,10 @@
   dependencies:
     "@types/koa" "*"
 
-"@types/koa@*", "@types/koa@2.0.49":
-  version "2.0.49"
-  resolved "https://registry.yarnpkg.com/@types/koa/-/koa-2.0.49.tgz#8ffc2ddbdd715a2c392a218c67e116cb07007234"
-  integrity sha512-WQWpCH8O4Dslk8IcXfazff40aM1jXX7BQRbADIj/fKozVPu76P/wQE4sRe2SCWMn8yNkOcare2MkDrnZqLMkPQ==
+"@types/koa@*", "@types/koa@2.0.50":
+  version "2.0.50"
+  resolved "https://registry.yarnpkg.com/@types/koa/-/koa-2.0.50.tgz#c295cbbd59f4898e7a8794c0f2e42e60da83aab2"
+  integrity sha512-TcgOD2lh0EISSadAk1DOBYw7kNoY9XdeB3vEMOKiDDaTMYm+V54nyPsU7Ulb/htb5OBIR79RgTeCWntCcophLw==
   dependencies:
     "@types/accepts" "*"
     "@types/cookies" "*"