Revert "microvm-init: mount defaultshare read-only, do not chmod moutpoint" (wolfi-dev#71153)

This reverts commit bb8213b.

This causes breakage when builds or tests happen as non root.

Ref: chainguard-dev/melange#2155

Author: stevebeattie

microvm-init.yaml

@@ -1,7 +1,7 @@
 package:
   name: microvm-init
   version: 0.0.1
-  epoch: 13
+  epoch: 14
   description: Minimal busybox init for microvm workloads
   copyright:
     - license: Apache-2.0
@@ -14,7 +14,6 @@ package:
       - kmod
       - mount
       - openssh-server
-      - umount
       - util-linux-misc
       - xfsprogs
 

microvm-init/init

@@ -93,9 +93,11 @@ mount -t 9p \
 	-o security_model=mapped-xattr \
 	-o posixacl=on \
 	-o msize=104857600 \
-	-o ro \
 	defaultshare /mount/mnt/
 
+# Allow the user we are running as to copy things to the shared dir
+chmod 0777 /mount/mnt
+
 mount --rbind /dev /mount/dev
 mount --rbind /proc /mount/proc
 mount --rbind /sys /mount/sys