Try use tmpfs for mysql volume (#641)

Author: adamchainz

.github/workflows/main.yml

@@ -33,10 +33,12 @@ jobs:
     services:
       database:
         image: ${{ matrix.database }}
-        ports:
-        - 3306:3306
         env:
           MYSQL_ROOT_PASSWORD: hunter2
+        ports:
+        - 3306:3306
+        volumes:
+        - type=tmpfs,destination=/var/lib/mysql
 
     env:
       DB_HOST: 127.0.0.1