Remove pipes module from LIT tests

[shahmishal]

The pipes module was removed in Python 3.13.

(cherry picked from commit 35b964c)

To unblock Fedora 41 CI. https://ci.swift.org/view/Swift%206.2/job/oss-swift-6.2-package-fedora-41/19/

[shahmishal]

@swift-ci test

[compnerd]

This doesn't work. shlex is not compatible with Windows and quotes command lines incorrectly.

(Ref: https://docs.python.org/3/library/shlex.html)

[shahmishal]

@compnerd This has been part of main branch since July, are we actively seeing an issue? #510

[compnerd]

Interesting - no, I don't think that I've seen an issue in the current usage, but I have definitely run into issues with shlex on Windows in the past and had to do work to remove it from the Swift repo's usage in the tests when I did the initial port.

[shahmishal]

Going to merge this PR. If we see any issues, feel free to revert this patch.

[da-viper]

@shahmishal could we cherry pick it into the 6.2.x branches as that is what is used in the fedora 6.2 ci