Deprecation warnings from `node-fetch` and `rimraf` in downstream consumers

[sherman-yang]

When consumers install libraries that transitively depend on gaxios (like google-auth-library), they see npm deprecation warnings:

npm warn deprecated node-domexception@1.0.0: Use your platform's native DOMException instead
npm warn deprecated rimraf@3.0.2: Rimraf versions prior to v4 are no longer supported
npm warn deprecated glob@7.2.3: Glob versions prior to v9 are no longer supported

These come from the node-fetch and rimraf dependencies. Moving gaxios to the native Node 18+ fetch API removes the node-fetch dependency tree and eliminates these transitive warnings for all consumers.

[benmccann]

rimraf is already removed but consumers are pinned to old versions of gaxios, so the pinning should be removed. For example:

google-cloud-node-core/packages/google-auth-library-nodejs/package.json

Line 26 in 7feb4c8

"gaxios": "7.1.3",

[benmccann]

Looks like there's a PR for it: #922

[AviVahl]

They've actually pinned the dependency version right before the new gaxios was released. Very frustrating.
See #903 (comment)

[AviVahl]

This was also reported in #921