test: prepare test/testpy/__init__.py for Python 3

[cclauss]

label: python

Checklist

• make -j4 test (UNIX), or vcbuild test (Windows) passes
• tests and/or benchmarks are included
• documentation is changed or added
• commit message follows commit guidelines

[Trott]

CI: https://ci.nodejs.org/job/node-test-pull-request/19255/

[Trott]

Resume Build CI; https://ci.nodejs.org/job/node-test-pull-request/19264/

[Trott]

Resume Build CI: https://ci.nodejs.org/job/node-test-pull-request/19291/

[Trott]

Full Rebuild CI: https://ci.nodejs.org/job/node-test-pull-request/19296/

[Trott]

Resume Build CI: https://ci.nodejs.org/job/node-test-pull-request/19301/

[Trott]

Resume Build CI: https://ci.nodejs.org/job/node-test-pull-request/19307/

[Trott]

Resume Build CI: https://ci.nodejs.org/job/node-test-pull-request/19369/

[Trott]

Resume Build CI: https://ci.nodejs.org/job/node-test-pull-request/19380/

[danbev]

Re-run of failing node-test-commit-aix 🛑
Re-run of failing node-test-commit-aix

[Trott]

"Force a rebuild"? Should we force push that commit out? Or is it valid?

[cclauss]

The code is valid. Ship it!

[Trott]

New CI since we have a new commit AND we've marked that pesky test-cli-syntax as unreliable: https://ci.nodejs.org/job/node-test-pull-request/19431/

[cclauss]

Duplicate: This change has already landed in #24954