pip-requirements.txt: bump edk2-basetools to 0.1.43
Bump the version of edk2-basetools in pip-requirements.txt to 0.1.43.
This version contains the update to generate makefiles with both
CFLAGS and BUILD_CFLAGS.
Signed-off-by: Rebecca Cran <rebecca@bsdio.com>
Reviewed-by: Michael D Kinney <michael.d.kinney@intel.com>