V8 CI is broken

[richardlau]

V8 CI is broken (looks like we're still trying to run it with Python 2.7)

Originally posted by @targos in #48710 (comment)

[richardlau]

Seems to have started failing last Friday
e.g. https://ci.nodejs.org/job/node-test-commit-v8-linux/5432/
https://ci.nodejs.org/job/node-test-commit-v8-linux/5432/nodes=rhel8-s390x,v8test=v8test/console

10:34:50 + ../../tools/v8/fetch_deps.py .
10:34:50 Cloning into '/home/iojs/build/workspace/node-test-commit-v8-linux/deps/v8/_depot_tools'...
10:34:53   File "/home/iojs/build/workspace/node-test-commit-v8-linux/deps/v8/_depot_tools/gclient.py", line 3461
10:34:53     f'160000,{value},{name}'
10:34:53                            ^
10:34:53 SyntaxError: invalid syntax
10:34:53 Checking out depot_tools.
10:34:53 Traceback (most recent call last):
10:34:53   File "../../tools/v8/fetch_deps.py", line 100, in <module>
10:34:53     FetchDeps(sys.argv[1])
10:34:53   File "../../tools/v8/fetch_deps.py", line 72, in FetchDeps
10:34:53     depot_tools = node_common.EnsureDepotTools(v8_path, True)
10:34:53   File "/home/iojs/build/workspace/node-test-commit-v8-linux/tools/v8/node_common.py", line 40, in EnsureDepotTools
10:34:53     depot_tools = _Get(v8_path)
10:34:53   File "/home/iojs/build/workspace/node-test-commit-v8-linux/tools/v8/node_common.py", line 37, in _Get
10:34:53     cwd=depot_tools)
10:34:53   File "/usr/lib64/python2.7/subprocess.py", line 223, in check_output
10:34:53     raise CalledProcessError(retcode, cmd, output=output)
10:34:53 subprocess.CalledProcessError: Command '['/usr/bin/python', '/home/iojs/build/workspace/node-test-commit-v8-linux/deps/v8/_depot_tools/gclient.py', 'metrics', '--opt-out']' returned non-zero exit status 1
10:34:53 make: *** [Makefile:303: v8] Error 1

It's a bit of a surprise that we are still running fetch_deps.py with Python 2. I'll open a PR to update.

[richardlau]

Opened #48729.
Also needs some updates on the build infrastructure (already applied): nodejs/build#3418