Restore installing the MySQL client

Works around a (temporary) issue with the GitHub instances. See
actions/runner-images#5067 for details.

.github/ubuntu/all-apt-prereqs.sh

@@ -1,11 +1,12 @@
 set -e
 
 sudo apt-get update -qq
+sudo apt-get remove -qq mysql-common # https://github.com/actions/virtual-environments/issues/5067#issuecomment-1038752575
 sudo env DEBIAN_FRONTEND=noninteractive apt-get install -qq \
     libicu-dev gettext aspell-en software-properties-common \
     curl unixodbc-dev odbcinst unixodbc \
     default-jre \
     firebird-dev firebird3.0-utils \
+    mysql-client default-libmysqlclient-dev \
     libarchive-tools
-    # mysql-client default-libmysqlclient-dev \
 cat t/odbc/odbcinst.ini | sudo tee -a /etc/odbcinst.ini

.github/ubuntu/mysql.sh

@@ -5,5 +5,6 @@ set -e
 # Download dependencies.
 if [ -z "$SKIP_DEPENDS" ]; then
     sudo apt-get update -qq
+    sudo apt-get remove -qq mysql-common # https://github.com/actions/virtual-environments/issues/5067#issuecomment-1038752575
     sudo env DEBIAN_FRONTEND=noninteractive apt-get install -qq mysql-client default-libmysqlclient-dev
 fi

.github/workflows/coverage.yml

@@ -52,7 +52,7 @@ jobs:
           .github/ubuntu/all-apt-prereqs.sh
           .github/ubuntu/exasol.sh
           .github/ubuntu/firebird.sh
-          # .github/ubuntu/mysql.sh
+          .github/ubuntu/mysql.sh
           .github/ubuntu/oracle.sh
           .github/ubuntu/pg.sh
           .github/ubuntu/snowflake.sh

.github/workflows/mysql.yml

@@ -36,8 +36,8 @@ jobs:
         options: --health-cmd="mysqladmin ping" --health-interval=5s --health-timeout=2s --health-retries=3
     steps:
       - uses: actions/checkout@v2
-      # - name: Setup Clients
-      #   run: .github/ubuntu/mysql.sh
+      - name: Setup Clients
+        run: .github/ubuntu/mysql.sh
       - name: Setup Perl
         id: perl
         uses: shogo82148/actions-setup-perl@v1