Remove hack that mounted /dev/shm with exec, dosemu2 no longer needs it (#1334)

.github/workflows/ci.yml

@@ -182,7 +182,6 @@ jobs:
             -v $(pwd)/local_files:/local_files \
             -v $(pwd)/compilers:/compilers \
             -v $(pwd)/libraries:/libraries \
-            --tmpfs /dev/shm:exec,uid=1000,gid=1000,size=64M,mode=0700 \
             --security-opt apparmor=unconfined \
             --security-opt seccomp=unconfined \
             --entrypoint /bin/bash \

docker-compose.yaml

@@ -46,8 +46,6 @@ services:
     volumes:
       - ./backend:/backend
     tmpfs:
-      # explicitly mount /dev/shm with exec as dosemu2 requires exec privilege
-      - /dev/shm:exec,uid=1000,gid=1000,size=64M,mode=0700
       # Use a separate tmpfs to prevent a rogue jailed process
       # from filling /tmp on the parent container
       - /sandbox/tmp:exec,uid=1000,gid=1000,size=64M,mode=0700