python-3.7.6: Change tmpdir

We are going to install Tensorflow into this package. The compilation of
Tendowflow produces huge amounts of data (335612 files, 35 GB) in
~/.cache/bazel.

Change BUILD_TMPDIR (which implies $HOME during the build) away from
/dev/shm to avoid running out of memory.

python-3.7.6-0.build.sh

@@ -15,7 +15,7 @@ PATH=/bin:/usr/bin:/usr/sbin:/usr/local/bin
 set -xe
 umask 022
 
-BUILD_TMPDIR=/dev/shm/$PKG-$VERSION-$BUILD.build.tmp
+BUILD_TMPDIR=/scratch/local2/$PKG-$VERSION-$BUILD.build.tmp
 test -d $BUILD_TMPDIR && ( chmod -R u+rwx $BUILD_TMPDIR || true ; rm -rf $BUILD_TMPDIR )
 mkdir -p $BUILD_TMPDIR/home
 export TMPDIR=$BUILD_TMPDIR