lang/python3([6-9]|10): disable detection of multiarch

It breaks with clang >= 13, which adds a major.minor version number in
-print-multiarch output, and the dot confuses Python:

ModuleNotFoundError: No module named '_sysconfigdata__freebsd14_x86_64-unknown-freebsd14'

Since we do not support multiarch, and the configure script has no way
to disable the multiarch check, stub it out during post-patch.

PR:		258377
Approved by:	maintainer timeout (2 weeks)
MFH:		2021Q3

lang/python310/Makefile

@@ -124,6 +124,10 @@ post-patch:
 # which introduces hidden dependency and breaks build
 	@${REINPLACE_CMD} -e 's|uuid/uuid.h|ignore_&|' ${WRKSRC}/configure
 	@${REINPLACE_CMD} -e '/find_library_file/ s|uuid|ignore_&|' ${WRKSRC}/setup.py
+# disable detection of multiarch as it breaks with clang >= 13, which adds a
+# major.minor version number in -print-multiarch output, confusing Python
+	@${REINPLACE_CMD} -e 's|^MULTIARCH=.*|MULTIARCH=|' ${WRKSRC}/configure \
+		${WRKSRC}/configure.ac
 # Apply DISABLED_EXTENSIONS
 	@${ECHO_CMD} '*disabled*' > ${WRKSRC}/Modules/Setup.local
 .  for _module in ${DISABLED_EXTENSIONS}