GHA: misc updates: impacket, timeouts, mingw-w64 32-bit

- NetBSD: enable impacket. Debatable if this hefty package is worth it
  for the single SMB test (1451) run curl uses it for.
  (on the upside, it seems to install instantly on NetBSD)
  It's also a versioned package name that requires active maintenance.
  The unversioned name doesn't work, though that's what the package
  search returns: https://pkgsrc.se/net/py-impacket

- FreeBSD: stop installing impacket deps explicitly.
  They are automatically installed via the impacket package.

- Linux: put time limit on test runs.
  Started hanging yesterday:
  linux: https://github.com/curl/curl/actions/runs/10875011573/job/30172946986#step:41:3731
  awslc: https://github.com/curl/curl/actions/runs/10879782864/job/30185188509
  wolfssl: https://github.com/curl/curl/actions/runs/10879782864/job/30185188509

- distcheck: reduce time limit to 15m (was 30m)
  Linux tests started to hang, so reduce the timeout from 30 minutes
  to 15. These jobs normally take 3 to 6 minutes to finish.
  https://github.com/curl/curl/actions/runs/10879479914

- Windows: add 32-bit MSYS2/mingw-w64 job.
  Follow-up to e53523fef0 #14859

Closes #14929

.github/workflows/linux.yml

@@ -549,6 +549,7 @@ jobs:
 
       - name: 'run tests'
         if: ${{ matrix.build.install_steps != 'skipall' && matrix.build.install_steps != 'skiprun' }}
+        timeout-minutes: ${{ contains(matrix.build.install_packages, 'valgrind') && 30 || 15 }}
         run: |
           export TFLAGS='${{ matrix.build.tflags }}'
           if [[ '${{ matrix.build.install_packages }}' = *'heimdal-dev'* ]]; then