[DevDependency] Bump karma-sourcemap-loader from 0.3.8 to 0.4.0 (#665)

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

Author: dependabot[bot]

package-lock.json

@@ -52,7 +52,7 @@
     "karma-firefox-launcher": "^2.1.1",
     "karma-mocha": "^2.0.0",
     "karma-sinon-chai": "^2.0.2",
-    "karma-sourcemap-loader": "^0.3.7",
+    "karma-sourcemap-loader": "^0.4.0",
     "karma-webpack": "^4.0.2",
     "mocha": "^10.4.0",
     "pdfjs-dist": "4.3.136",