build(deps): bump mixin-deep in /ihaskell_labextension

Bumps [mixin-deep](https://github.com/jonschlinkert/mixin-deep) from 1.3.1 to 1.3.2.
- [Release notes](https://github.com/jonschlinkert/mixin-deep/releases)
- [Commits](https://github.com/jonschlinkert/mixin-deep/compare/1.3.1...1.3.2)
Signed-off-by: dependabot[bot] <support@github.com>

ihaskell_labextension/package-lock.json

@@ -2836,9 +2836,9 @@
       }
     },
     "mixin-deep": {
-      "version": "1.3.1",
-      "resolved": "https://registry.npmjs.org/mixin-deep/-/mixin-deep-1.3.1.tgz",
-      "integrity": "sha1-pJ5yaNzhoNlpjkUybFYm3zVD0P4=",
+      "version": "1.3.2",
+      "resolved": "https://registry.npmjs.org/mixin-deep/-/mixin-deep-1.3.2.tgz",
+      "integrity": "sha512-WRoDn//mXBiJ1H40rqa3vH0toePwSsGb45iInWlTySa+Uu4k3tYUSxa2v1KqAiLtvlrSzaExqS1gtk96A9zvEA==",
       "dev": true,
       "requires": {
         "for-in": "^1.0.2",
@@ -2848,7 +2848,7 @@
         "is-extendable": {
           "version": "1.0.1",
           "resolved": "https://registry.npmjs.org/is-extendable/-/is-extendable-1.0.1.tgz",
-          "integrity": "sha1-p0cPnkJnM9gb2B4RVSZOOjUHyrQ=",
+          "integrity": "sha512-arnXMxT1hhoKo9k1LZdmlNyJdDDfy2v0fXjFlmok4+i8ul/6WlbVge9bhM74OpNPQPMGUToDtz+KXa1PneJxOA==",
           "dev": true,
           "requires": {
             "is-plain-object": "^2.0.4"