Bump yarn from 1.22.19 to 1.22.21

Bumps [yarn](https://github.com/yarnpkg/yarn) from 1.22.19 to 1.22.21.
- [Release notes](https://github.com/yarnpkg/yarn/releases)
- [Changelog](https://github.com/yarnpkg/yarn/blob/master/CHANGELOG.md)
- [Commits](yarnpkg/yarn@v1.22.19...v1.22.21)

---
updated-dependencies:
- dependency-name: yarn
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

package.json

@@ -20,7 +20,7 @@
     "masonry-layout": "^4.2.2",
     "popper.js": "^1.16.1",
     "shariff": "^3.3.0",
-    "yarn": "^1.22.19"
+    "yarn": "^1.22.21"
   },
   "scripts": {
     "build:css:sass": "sass wger/core/static/scss/main.scss:wger/core/static/yarn/bootstrap-compiled.css"

yarn.lock

@@ -381,7 +381,7 @@ shariff@^3.3.0:
     "@fortawesome/fontawesome-free" "^5.8.2"
     jquery "^3.4.1"
 
-yarn@^1.22.19:
-  version "1.22.19"
-  resolved "https://registry.yarnpkg.com/yarn/-/yarn-1.22.19.tgz#4ba7fc5c6e704fce2066ecbfb0b0d8976fe62447"
-  integrity sha512-/0V5q0WbslqnwP91tirOvldvYISzaqhClxzyUKXYxs07yUILIs5jx/k6CFe8bvKSkds5w+eiOqta39Wk3WxdcQ==
+yarn@^1.22.21:
+  version "1.22.21"
+  resolved "https://registry.yarnpkg.com/yarn/-/yarn-1.22.21.tgz#1959a18351b811cdeedbd484a8f86c3cc3bbaf72"
+  integrity sha512-ynXaJsADJ9JiZ84zU25XkPGOvVMmZ5b7tmTSpKURYwgELdjucAOydqIOrOfTxVYcNXe91xvLZwcRh68SR3liCg==