Bump mobx from 6.7.0 to 6.8.0 (#7170)

Bumps [mobx](https://github.com/mobxjs/mobx) from 6.7.0 to 6.8.0.
- [Release notes](https://github.com/mobxjs/mobx/releases)
- [Commits](https://github.com/mobxjs/mobx/commits)

---
updated-dependencies:
- dependency-name: mobx
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

packages/core/package.json

@@ -163,7 +163,7 @@
     "lodash": "^4.17.15",
     "marked": "^4.2.12",
     "md5-file": "^5.0.0",
-    "mobx": "^6.7.0",
+    "mobx": "^6.8.0",
     "mobx-observable-history": "^2.0.3",
     "mobx-react": "^7.6.0",
     "mobx-utils": "^6.0.4",

packages/core/yarn.lock

@@ -8941,10 +8941,10 @@ mobx-utils@^6.0.4:
   resolved "https://registry.yarnpkg.com/mobx-utils/-/mobx-utils-6.0.5.tgz#0cce9afb07fbba1fb559f959f8cea1f44baa7252"
   integrity sha512-QOduwicYedD4mwYZRl8+c3BalljFDcubg+PUGqBkn8tOuBoj2q7GhjXBP6JXM9J+Zh+2mePK8IoToeLfqr3Z/w==
 
-mobx@^6.3.0, mobx@^6.7.0:
-  version "6.7.0"
-  resolved "https://registry.yarnpkg.com/mobx/-/mobx-6.7.0.tgz#2d805610fee1801fd015c54fd5400d2601aa3768"
-  integrity sha512-1kBLBdSNG2bA522HQdbsTvwAwYf9hq9FWxmlhX7wTsJUAI54907J+ozfGW+LoYUo06vjit748g6QH1AAGLNebw==
+mobx@^6.3.0, mobx@^6.8.0:
+  version "6.8.0"
+  resolved "https://registry.yarnpkg.com/mobx/-/mobx-6.8.0.tgz#59051755fdb5c8a9f3f2e0a9b6abaf86bab7f843"
+  integrity sha512-+o/DrHa4zykFMSKfS8Z+CPSEg5LW9tSNGTuN8o6MF1GKxlfkSHSeJn5UtgxvPkGgaouplnrLXCF+duAsmm6FHQ==
 
 mock-http@^1.1.0:
   version "1.1.0"