Lock MySQL Docker image to 8.0.28.

There may be a regression in 8.0.29 that's breaking the tests and needs to be investigated further.

Author: bgrainger

.ci/docker-run.sh

@@ -24,7 +24,7 @@ PORT=$2
 OMIT_FEATURES=$3
 MYSQL_EXTRA=
 
-if [ "$IMAGE" == "mysql:8.0" ]; then
+if [ "$IMAGE" == "mysql:8.0.28" ]; then
   MYSQL_EXTRA='--default-authentication-plugin=mysql_native_password'
 fi
 if [[ "$IMAGE" == mariadb* ]]; then

azure-pipelines.yml

@@ -223,7 +223,7 @@ jobs:
         image: 'mysql:5.7'
         unsupportedFeatures: 'CachingSha2Password,Ed25519,QueryAttributes,Tls11,Tls13,UuidToBin'
       'MySQL 8.0':
-        image: 'mysql:8.0'
+        image: 'mysql:8.0.28'
         unsupportedFeatures: 'Ed25519,Tls11,ZeroDateTime'
       'MariaDB 10.4':
         image: 'mariadb:10.4'