handling PEP668 better ("break-system-packages")

[kingspride]

Another Pull-Request from me regarding the procServUtils...
it fixes an oversight in my #60 PR:

python and corresponding pip versions below 3.11 fail to install procServUtils because they dont know the option --break-system-packages

thus, I switched the logic to an environment variable PIP_BREAK_SYSTEM_PACKAGES=1.
it gets ignored by the old versions and the newer ones still allow installation of the package.

thanks for merging ;)

[mdavidsaver]

As of July 2025, pip v25.1.1 still documents --break-system-packages, and does not include a deprecation notice. (It also mentions $PIP_BREAK_SYSTEM_PACKAGES)

[ralphlange]

Correct, but this is about older versions of pip not knowing the commandline option (which fails) and ignoring the environment variable (which works).