format ESP using mformat

Dockerfile

@@ -1,7 +1,7 @@
 from novit.tech/direktil/dkl:v1.2.0 as dkl
 
 # ------------------------------------------------------------------------
-from golang:1.26.1-trixie as build
+from golang:1.26.4-trixie as build
 
 run apt-get update && apt-get install -y git
 
@@ -27,11 +27,11 @@ from debian:trixie
 entrypoint ["/bin/dkl-local-server"]
 
 env _uncache=1
-run apt update \
+run --mount=type=cache,id=debian-trixie-apt,target=/var/cache/apt \
+ apt update \
  && yes |apt install -y genisoimage gdisk dosfstools util-linux udev binutils systemd \
  grub2 grub-pc-bin grub-efi-amd64-bin ca-certificates curl openssh-client qemu-utils wireguard-tools \
- erofs-utils erofsfuse cryptsetup systemd-boot-efi \
- && apt clean
+ erofs-utils erofsfuse cryptsetup systemd-boot-efi mtools
 
 copy --from=dkl   /bin/dkl /bin/dls /bin/
 copy --from=build /src/dist/ /bin/