docker: no longer install fuse2 to get fusermount

fusermount3 works as expected

Dockerfile

@@ -25,9 +25,6 @@ RUN apk add --no-cache \
 
 RUN echo user_allow_other >> /etc/fuse.conf
 
-# optional, contains fusermount
-RUN apk add --no-cache fuse
-
 RUN adduser -S encrypt
 USER encrypt