chore(deps): update dependency @grpc/proto-loader to ^0.4.0 (#957)

Author: renovate[bot]

package.json

@@ -48,7 +48,7 @@
     "node": ">=6"
   },
   "devDependencies": {
-    "@grpc/proto-loader": "^0.3.0",
+    "@grpc/proto-loader": "^0.4.0",
     "@types/builtin-modules": "^2.0.0",
     "@types/console-log-level": "^1.4.0",
     "@types/continuation-local-storage": "^3.2.1",

test/test-grpc-async-handler.ts

@@ -36,7 +36,7 @@ describeInterop<Grpc>('grpc', (fixture) => {
     grpc = fixture.require();
     const proto =
         await protoLoader.load(`${__dirname}/fixtures/test-grpc.proto`);
-    testerService = proto['nodetest.Tester'];
+    testerService = proto['nodetest.Tester'] as protoLoader.ServiceDefinition;
   });
 
   afterEach(() => {