runner.pm: run memanalyzer as a Perl module

runner.pm: run memanalyzer as a Perl module

To improve performance of torture tests.

Also on Windows, where this patch may make those viable for CI.

Linux   !FTP    4m47 ->  4m24 (-shallow=25)
Linux    FTP    2m30 ->  2m23 (-shallow=25)
macOS   !FTP   14m30 -> 13m07 (-shallow=25)
macOS    FTP    3m57 ->  3m59 (-shallow=25)
Windows !FTP  >25m   ->  4m47 to 14m45 (-shallow=5 to 25) (not in CI)

Linux
Before: https://github.com/curl/curl/actions/runs/20006771767/job/57370205514
After: https://github.com/curl/curl/actions/runs/20006783210/job/57370236911?pr=19863

macOS:
Before: https://github.com/curl/curl/actions/runs/20006771786/job/57370205769
After: https://github.com/curl/curl/actions/runs/20006783177/job/57370236995?pr=19863

Windows:
Before: https://github.com/curl/curl/actions/runs/19667198537/job/56326962912?pr=19675
After: https://github.com/curl/curl/actions/runs/20007175773/job/57371768734?pr=19863
After shallow=25: https://github.com/curl/curl/actions/runs/20008523913/job/57374427449?pr=19865

Ref: #19675
Follow-up to 472bc9032374f98f48f7a2df6c644cff91fe142c #19821
Closes #19863