Merge pull request #14732 from jakesmith/hpcc-25601-add-sql-client-lib

HPCC-25601 Add missing mysql client lib to platform-core

Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>

dockerfiles/platform-core/Dockerfile

@@ -38,6 +38,7 @@ RUN apt-get install -y \
   libpython3.8 \
   libmemcached11 \
   libmemcachedutil2 \
+  libmysqlclient21 \
   libxslt1.1 \
   locales \
   python \