gh-146609: Add colour to timeit CLI output

[hugovk]

Standard and verbose:

./python.exe -m timeit "'-'.join(str(n) for n in range(100))"
./python.exe -m timeit --verbose "'-'.join(str(n) for n in range(100))"

With a warning:

./python.exe -m timeit "import time, random; time.sleep(random.random() * 0.9)"

As usual, environment variables can control colour output.

• Issue: Add colour to timeit CLI output #146609

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📚 Documentation preview 📚: https://cpython-previews--146610.org.readthedocs.build/

[ambv]

Nitpick: I would segment this differently. The fact that the entire line after "raw times:" is just cyan is a wasted opportunity. Would make sense to me to make the commas delimiting the values be colored the same way as the arrows.

[hugovk]

Like this?