d/tests/pytest: Run against all supported python3 versions.

Also move from the deprecated ADTTMP to AUTOPKGTEST_TMP.

Signed-off-by: Mattia Rizzolo <mattia@debian.org>
4 jobs for master in 20 minutes and 40 seconds (queued for 6 seconds)
Status Job ID Name Coverage
  Test
passed #369141
stable-bpo

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passed #369140
testing

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passed #369142
allowed to fail
ubuntu-devel

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passed #369139
unstable

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88.0%