Bump ts-loader from 8.0.3 to 8.0.4

Bumps [ts-loader](https://github.com/TypeStrong/ts-loader) from 8.0.3 to 8.0.4.
- [Release notes](https://github.com/TypeStrong/ts-loader/releases)
- [Changelog](https://github.com/TypeStrong/ts-loader/blob/master/CHANGELOG.md)
- [Commits](https://github.com/TypeStrong/ts-loader/compare/v8.0.3...8.0.4)

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

package.json

@@ -47,7 +47,7 @@
         "replace-in-file-webpack-plugin": "^1.0.6",
         "terser-webpack-plugin": "^4.2.2",
         "tfx-cli": "^0.8.3",
-        "ts-loader": "^8.0.3",
+        "ts-loader": "^8.0.4",
         "typescript": "^4.0.3",
         "webpack": "^4.44.2",
         "webpack-cli": "^3.3.12"