Some noxfile.py files are still using blacken

[jskeet]

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Summary of the issue

We should use the same code formatting across all packages.

Currently, 7 packages don't use ruff:

$ grep -L ruff packages/*/noxfile.py

Results:

• packages/google-api-core/noxfile.py
• packages/google-auth-httplib2/noxfile.py
• packages/google-auth-oauthlib/noxfile.py
• packages/google-cloud-core/noxfile.py
• packages/google-cloud-dns/noxfile.py
• packages/google-cloud-runtimeconfig/noxfile.py
• packages/google-cloud-testutils/noxfile.py
• packages/proto-plus/noxfile.py

API client name and version

No response

Reproduction steps: code

file: main.py

   def reproduce():
    # complete code here

Reproduction steps: supporting files

file: mydata.csv

alpha,1,3
beta,2,5

Reproduction steps: actual results

file: output.txtmydata.csv

Calculated: foo

Reproduction steps: expected results

file: output.txtmydata.csv

Calculated: bar

OS & version + platform

No response

Python environment

No response

Python dependencies

No response

Additional context

No response