"Error: Could not read source directory" can mask network errors

When I run a lot of firebase deploys (functions) in a short period of time, I get the error message "Error: Could not read source directory. Remove links and shortcuts and try again". But it seems that this is not because source directory but because Google checks unusual traffic. I get an HTML page response, but I can't deal with it because I am accessing it through the CLI from a server. I would like to know if there is a way to avoid this.

### [REQUIRED] Environment info

**firebase-tools:**
9.0.1

**Platform:** Ubuntu
(20.04.1 LTS)

### [REQUIRED] Test case

none

### [REQUIRED] Steps to reproduce

Run firebase deploy many times in a short period of time

### [REQUIRED] Expected behavior

I expect deploy finish without error or get proper error message.

### [REQUIRED] Actual behavior

```
=== Deploying to ''...

i deploying functions
[2020-12-21T03:01:36.059Z] > [functions] package.json contents: {
...
}
[2020-12-21T03:01:36.493Z] getFunctionsSDKVersion was unable to retrieve 'firebase-functions' version
i functions: ensuring required API cloudfunctions.googleapis.com is enabled...
i functions: ensuring required API cloudbuild.googleapis.com is enabled...
[2020-12-21T03:01:36.495Z] >>> HTTP REQUEST GET https://serviceusage.googleapis.com/v1/projects//services/cloudfunctions.googleapis.com

[2020-12-21T03:01:36.496Z] >>> HTTP REQUEST GET https://serviceusage.googleapis.com/v1/projects//services/runtimeconfig.googleapis.com

[2020-12-21T03:01:36.496Z] >>> HTTP REQUEST GET https://serviceusage.googleapis.com/v1/projects//services/cloudbuild.googleapis.com

[2020-12-21T03:01:36.828Z] <<< HTTP RESPONSE 200 {"content-type":"application/json; charset=UTF-8","vary":"X-Origin, Referer, Origin,Accept-Encoding","date":"Mon, 21 Dec 2020 03:01:36 GMT","server":"ESF","cache-control":"private","x-xss-protection":"0","x-frame-options":"SAMEORIGIN","x-content-type-options":"nosniff","accept-ranges":"none","transfer-encoding":"chunked"}
✔ functions: required API cloudbuild.googleapis.com is enabled
[2020-12-21T03:01:37.415Z] <<< HTTP RESPONSE 200 {"content-type":"application/json; charset=UTF-8","vary":"X-Origin, Referer, Origin,Accept-Encoding","date":"Mon, 21 Dec 2020 03:01:37 GMT","server":"ESF","cache-control":"private","x-xss-protection":"0","x-frame-options":"SAMEORIGIN","x-content-type-options":"nosniff","accept-ranges":"none","transfer-encoding":"chunked"}
✔ functions: required API cloudfunctions.googleapis.com is enabled
[2020-12-21T03:01:37.430Z] <<< HTTP RESPONSE 200 {"content-type":"application/json; charset=UTF-8","vary":"X-Origin, Referer, Origin,Accept-Encoding","date":"Mon, 21 Dec 2020 03:01:37 GMT","server":"ESF","cache-control":"private","x-xss-protection":"0","x-frame-options":"SAMEORIGIN","x-content-type-options":"nosniff","accept-ranges":"none","transfer-encoding":"chunked"}
[2020-12-21T03:01:37.431Z] >>> HTTP REQUEST GET https://firebase.googleapis.com/v1beta1/projects//adminSdkConfig

[2020-12-21T03:01:37.914Z] <<< HTTP RESPONSE 200 {"content-type":"application/json; charset=UTF-8","vary":"X-Origin, Referer, Origin,Accept-Encoding","date":"Mon, 21 Dec 2020 03:01:37 GMT","server":"ESF","cache-control":"private","x-xss-protection":"0","x-frame-options":"SAMEORIGIN","x-content-type-options":"nosniff","accept-ranges":"none","transfer-encoding":"chunked"}
i functions: preparing ./packages/functions/build directory for uploading...
[2020-12-21T03:01:37.917Z] >>> HTTP REQUEST GET https://runtimeconfig.googleapis.com/v1beta1/projects//configs

[2020-12-21T03:01:38.789Z] <<< HTTP RESPONSE 429 {"date":"Mon, 21 Dec 2020 03:01:38 GMT","pragma":"no-cache","expires":"Fri, 01 Jan 1990 00:00:00 GMT","cache-control":"no-store, no-cache, must-revalidate","content-type":"text/html","server":"HTTP server (unknown)","content-length":"2919","x-xss-protection":"0"}
[2020-12-21T03:01:38.789Z] <<< HTTP RESPONSE BODY

https://runtimeconfig.googleapis.com/v1beta1/projects/<PROJECT_ID>/configs

[2020-12-21T03:01:38.791Z] FirebaseError: HTTP Error: 429, Unknown Error
[2020-12-21T03:01:40.223Z] Error: input source must be valid Stream or Buffer instance
at Archiver.append (/node_modules/archiver/lib/core.js:575:24)
at /node_modules/firebase-tools/lib/prepareFunctionsUpload.js:63:17
at processTicksAndRejections (internal/process/task_queues.js:97:5)
at async deploy (/node_modules/firebase-tools/lib/deploy/functions/deploy.js:25:24)

Error: Could not read source directory. Remove links and shortcuts and try again.
```