Add patch to fix crosscompilation failure on uca-dump (Closes: #1029165)

Current mainline fails to cross-compile, which is also visible in the Salsa-CI run.

make[4]: Entering directory '/builds/mariadb-team/mariadb-server/debian/output/source_dir/builddir'
391[ 44%] Generating ctype-uca1400data.h
392cd /builds/mariadb-team/mariadb-server/debian/output/source_dir/builddir/strings && uca-dump --name-prefix=uca1400 --levels=3 /builds/mariadb-team/mariadb-server/debian/output/source_dir/mysql-test/std_data/unicode/allkeys1400.txt > ctype-uca1400data.h
393/bin/sh: 1: uca-dump: not found

This patch fixes it, as validated with a passing test-crossbuild-arm64 CI job. I also validated on Launchpad that there are no regressions on any architecture: