test custom vm-builder version in preparation for monitor

[fprasx]

Problem

Sourcing a custom vm-builder version that supports the monitor. This is part of a greater change that will move upscaling/downscaling functionality from the vm-informant to compute_ctl.
Related to neondatabase/autoscaling#362

Eventually, this change should be reverted once autoscaling/main's version of vm-builder supports the monitor - a change currently included in neondatabase/autoscaling#362.

Summary of changes

Checklist before requesting a review

• I have performed a self-review of my code.
• If it is a core feature, I have added thorough tests.
• Do we need to implement analytics? if so did you add the relevant metrics to the dashboard?
• If this PR requires public announcement, mark it with /release-notes label and add several sentences in this section.

Checklist before merging

• Do not forget to reformat commit message to not include the above checklist

[github-actions]

1016 tests run: 973 passed, 0 failed, 43 skipped (full report)

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Flaky tests (1)

Postgres 15

• test_remote_storage_upload_queue_retries[local_fs]: release

_{The comment gets automatically updated with the latest test results
62c26e6 at 2023-07-06T17:54:05.207Z :recycle:}

[fprasx]

Closing as superseded by neondatabase/autoscaling#477