fix(dep): update dependency p-limit to v3 (#902)

Author: laljikanjareeya

package.json

@@ -51,7 +51,7 @@
     "extend": "^3.0.2",
     "findit2": "^2.2.3",
     "gcp-metadata": "^4.0.0",
-    "p-limit": "^2.2.0",
+    "p-limit": "^3.0.1",
     "semver": "^7.0.0",
     "source-map": "^0.6.1",
     "split": "^1.0.0"

src/agent/io/sourcemapper.ts

@@ -13,7 +13,7 @@
 // limitations under the License.
 
 import * as fs from 'fs';
-import pLimit from 'p-limit';
+import pLimit = require('p-limit');
 import * as path from 'path';
 import {promisify} from 'util';
 import * as sourceMap from 'source-map';