python3 spkg-configure.m4: Do not reject python based on sysconfig LDFLAGS containing "-L." #31358
Description
(follow up from #31132)
gentoo appears to use this flag (as reported in https://groups.google.com/g/sage-release/c/hVIsURxpdhc/m/MS1Km9GHBAAJ), which is redundant but harmless.
CC: @strogdon
Component: build: configure
Author: Matthias Koeppe
Branch/Commit: 18a7d18
Reviewer: Steven Trogdon
Issue created by migration from https://trac.sagemath.org/ticket/31358