Revert "Add HOME env variable to cloudbuild so vpython can move forward."

This reverts commit feb3fc29b325f911768ba6dfd85e41874ebffc36.

Reason for revert: Might have broken the wasm cloudbuild.

Original change's description:
> Add HOME env variable to cloudbuild so vpython can move forward.
> 
> Bug: skia:9348
> Change-Id: Ic9d835f38b028c9a60f07b56f52527bcb440c454
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/236918
> Reviewed-by: Joe Gregorio <jcgregorio@google.com>
> Commit-Queue: Joe Gregorio <jcgregorio@google.com>

TBR=borenet@google.com,jcgregorio@google.com

Change-Id: I678e7027ad5f60a57b38c5d375ba16498b2cfa95
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: skia:9348
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/237037
Reviewed-by: Joe Gregorio <jcgregorio@google.com>
Commit-Queue: Joe Gregorio <jcgregorio@google.com>
1 file changed