pin setuptools to 7.0 to workaround brokenness in 8.x

setuptools 8.0 (and subsequently 8.0.1, 8.0.2) were released over the
weekend.  This introduces a breaking change whereby python packages
installed from SHA, rather than with a proper release version, do not
have their version numbers parsed properly due to the appended sha.
Eg python-glanceclient 0.14.2.2.gb126351

This commit:

- pins setuptools to 7.0, to workaround this issue until a fix
is made upstream, inside the global requirements.txt

- removes package installations of python-setuptools and
python-pip which had potential to further conflict.

- removes the list pip_common_packages from the all_common vars file

Closes-Bug: 1402679

Closes-Bug: 1402672

Change-Id: Idb75f816f47740ee28ec5d7d8afb118acf4a71bb
(cherry picked from commit 2793a1dbcb73d1ebc8ed31a6e75fc31506b0c4e8)
Merge "pin setuptools to 7.0 to workaround brokenness in 8.x" into stable/juno