Bump mirador from 3.3.0 to 3.4.2

Bumps [mirador](https://github.com/ProjectMirador/mirador) from 3.3.0 to 3.4.2.
- [Release notes](https://github.com/ProjectMirador/mirador/releases)
- [Commits](ProjectMirador/mirador@v3.3.0...v3.4.2)

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

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

package.json

@@ -146,7 +146,7 @@
     "lodash": "^4.17.21",
     "lru-cache": "^7.14.1",
     "markdown-it": "^13.0.1",
-    "mirador": "^3.3.0",
+    "mirador": "^3.4.2",
     "mirador-dl-plugin": "^0.13.0",
     "mirador-share-plugin": "^0.16.0",
     "morgan": "^1.10.0",