chore(deps-dev): bump protobufjs (#17)

Automatic merge of Dependabot PR

Author: dependabot[bot]

experimental/packages/otlp-transformer/package.json

@@ -69,7 +69,7 @@
     "mkdirp": "1.0.4",
     "mocha": "7.2.0",
     "nyc": "15.1.0",
-    "protobufjs": "6.11.4",
+    "protobufjs": "7.5.5",
     "rimraf": "3.0.2",
     "ts-loader": "8.3.0",
     "ts-mocha": "9.0.2",