Pin MySQL Version at 8.0.29 for upgrade/downgrade manual e2e test

This is needed as we do not currently plan on backporting the backup
fixes to v13 and older, thus release-13.0 will not ever get the
backup fixes to support 8.0.30+.

If we do decide to backport the fixes to release-13.0 then this
workflow change can be reverted.

Signed-off-by: Matt Lord <mattalord@gmail.com>

.github/workflows/upgrade_downgrade_test_backups_manual.yml

@@ -51,7 +51,7 @@ jobs:
     timeout-minutes: 40
     if: always() && (needs.get_previous_release.result == 'success')
     name: Run Upgrade Downgrade Test Backup Manual
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     needs:
       - get_upgrade_downgrade_label
       - get_previous_release
@@ -125,13 +125,29 @@ jobs:
         sudo deluser mysql
         sudo rm -rf /var/lib/mysql
         sudo rm -rf /etc/mysql
-        # Install mysql80
-        sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 467B942D3A79BD29
-        wget -c https://dev.mysql.com/get/mysql-apt-config_0.8.20-1_all.deb
-        echo mysql-apt-config mysql-apt-config/select-server select mysql-8.0 | sudo debconf-set-selections
-        sudo DEBIAN_FRONTEND="noninteractive" dpkg -i mysql-apt-config*
-        sudo apt-get update
-        sudo DEBIAN_FRONTEND="noninteractive" apt-get install -y mysql-server mysql-client
+
+        # Install MySQL 8.0
+        ####
+        ## Temporarily pin the MySQL version at 8.0.29 as Vitess 14.0 does not have the fix to support
+        ## backups of 8.0.30+. See: https://github.com/vitessio/vitess/pull/10847
+        ## TODO: remove this pin once the above fixes are backported to release-14.0 OR
+        ##       Vitess 16.0.0-SNAPSHOT becomes the dev version on vitessio/main
+        #sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 467B942D3A79BD29
+        #wget -c https://dev.mysql.com/get/mysql-apt-config_0.8.20-1_all.deb
+        #echo mysql-apt-config mysql-apt-config/select-server select mysql-8.0 | sudo debconf-set-selections
+        #sudo DEBIAN_FRONTEND="noninteractive" dpkg -i mysql-apt-config*
+        #sudo apt-get update
+        #sudo DEBIAN_FRONTEND="noninteractive" apt-get install -y mysql-server mysql-client
+        ####
+        wget -c https://cdn.mysql.com/archives/mysql-8.0/mysql-common_8.0.29-1ubuntu20.04_amd64.deb \
+                https://cdn.mysql.com/archives/mysql-8.0/mysql-community-client-core_8.0.29-1ubuntu20.04_amd64.deb \
+                https://cdn.mysql.com/archives/mysql-8.0/mysql-community-client-plugins_8.0.29-1ubuntu20.04_amd64.deb \
+                https://cdn.mysql.com/archives/mysql-8.0/mysql-client_8.0.29-1ubuntu20.04_amd64.deb \
+                https://cdn.mysql.com/archives/mysql-8.0/mysql-community-server-core_8.0.29-1ubuntu20.04_amd64.deb \
+                https://cdn.mysql.com/archives/mysql-8.0/mysql-community-server_8.0.29-1ubuntu20.04_amd64.deb \
+                https://cdn.mysql.com/archives/mysql-8.0/mysql-community-client_8.0.29-1ubuntu20.04_amd64.deb
+        sudo DEBIAN_FRONTEND="noninteractive" apt-get install -y ./mysql-*.deb
+
         # Install everything else we need, and configure
         sudo apt-get install -y make unzip g++ etcd curl git wget eatmydata grep
         sudo service mysql stop