fix: 🐛 Actually use bash for entrypoint

entrypoint.sh

@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/bin/bash
 
 set -ex
 
@@ -13,7 +13,7 @@ else
     MEMLIMIT=$(grep MemTotal /proc/meminfo | awk '{print $2 * 1024}')
 fi
 
-if ! [[ "$MEMLIMIT" =~ ^[0-9]+$ ]]; then
+if [[ $MEMLIMIT =~ ^[0-9]+$ ]]; then
     MEMLIMIT=$MEMSIZE
 fi