Bump karma from 6.3.13 to 6.3.15

Bumps [karma](https://github.com/karma-runner/karma) from 6.3.13 to 6.3.15.
- [Release notes](https://github.com/karma-runner/karma/releases)
- [Changelog](https://github.com/karma-runner/karma/blob/master/CHANGELOG.md)
- [Commits](https://github.com/karma-runner/karma/compare/v6.3.13...v6.3.15)

---
updated-dependencies:
- dependency-name: karma
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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

yarn.lock

@@ -8216,9 +8216,9 @@ karma-jasmine@~0.3.8:
   integrity sha1-W2RXeRrZuJqhc/B54+vhuMgFI2w=
 
 karma@~6.3.11:
-  version "6.3.13"
-  resolved "https://registry.yarnpkg.com/karma/-/karma-6.3.13.tgz#ff58622c4f913508dbf86506a5fc614be0e98137"
-  integrity sha512-64lbtHBnM/sG7XKvitSQVlImKYNugyjw4K2e8cZYrlZm0GwoWrfsrkzgS/KWY/r3+fVM/2xvT/JN6MyfdttxLw==
+  version "6.3.15"
+  resolved "https://registry.yarnpkg.com/karma/-/karma-6.3.15.tgz#6c3beedb2440b05589a502462140afed724481e7"
+  integrity sha512-4O5X6zVFdmwo/fgjRN84fPG3IvaiOxOjIeZBwBrQYz4nIyGqlF8Wm7C1Hr7idQ9NHgnvJM+LSjZwS1C+qALMGw==
   dependencies:
     body-parser "^1.19.0"
     braces "^3.0.2"
@@ -8235,6 +8235,7 @@ karma@~6.3.11:
     log4js "^6.4.1"
     mime "^2.5.2"
     minimatch "^3.0.4"
+    mkdirp "^0.5.5"
     qjobs "^1.2.0"
     range-parser "^1.2.1"
     rimraf "^3.0.2"