Fix CI issue MySQL GPG failed (#1198)

Please refer the bug logged at https://bugs.mysql.com/bug.php\?id\=106188 for more details

docker/kanister-mysql/image/Dockerfile

@@ -1,6 +1,11 @@
 ARG TOOLS_IMAGE
 FROM registry.access.redhat.com/ubi8/ubi:8.1 as builder
 RUN dnf install -y https://dev.mysql.com/get/mysql80-community-release-el8-1.noarch.rpm
+
+# GPG keys for MySQL have expired. Importing the new key below.
+# Please refer bug https://bugs.mysql.com/bug.php?id=106188 for more details
+RUN rpm --import https://repo.mysql.com/RPM-GPG-KEY-mysql-2022
+
 RUN dnf install -y mysql-community-client
 
 FROM $TOOLS_IMAGE