build(deps-dev): bump cross-env from 7.0.2 to 7.0.3

Bumps [cross-env](https://github.com/kentcdodds/cross-env) from 7.0.2 to 7.0.3.
- [Release notes](https://github.com/kentcdodds/cross-env/releases)
- [Changelog](https://github.com/kentcdodds/cross-env/blob/master/CHANGELOG.md)
- [Commits](https://github.com/kentcdodds/cross-env/compare/v7.0.2...v7.0.3)

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

yarn.lock

@@ -1666,10 +1666,10 @@
     yup "^0.29.3"
 
 "@backstage/core@^0.3.0":
-  version "0.4.2"
+  version "0.4.3"
   dependencies:
     "@backstage/config" "^0.1.2"
-    "@backstage/core-api" "^0.2.7"
+    "@backstage/core-api" "^0.2.8"
     "@backstage/theme" "^0.2.2"
     "@material-ui/core" "^4.11.0"
     "@material-ui/icons" "^4.9.1"
@@ -9927,9 +9927,9 @@ create-react-context@0.3.0:
     warning "^4.0.3"
 
 cross-env@^7.0.0:
-  version "7.0.2"
-  resolved "https://registry.npmjs.org/cross-env/-/cross-env-7.0.2.tgz#bd5ed31339a93a3418ac4f3ca9ca3403082ae5f9"
-  integrity sha512-KZP/bMEOJEDCkDQAyRhu3RL2ZO/SUVrxQVI0G3YEQ+OLbRA3c6zgixe8Mq8a/z7+HKlNEjo8oiLUs8iRijY2Rw==
+  version "7.0.3"
+  resolved "https://registry.npmjs.org/cross-env/-/cross-env-7.0.3.tgz#865264b29677dc015ba8418918965dd232fc54cf"
+  integrity sha512-+/HKd6EgcQCJGh2PSjZuUitQBQynKor4wrFbRg4DtAgS1aWO+gU52xpH7M9ScGgXSYmAVS9bIJ8EzuaGw0oNAw==
   dependencies:
     cross-spawn "^7.0.1"