[BUG] Not removing entries from /etc/fstab

Description
The mount states are not correctly removing entries from /etc/fstab, leading to duplicates.

Setup

/mnt/test:
  mount.mounted:
    - device: 'sshfs#me@host:/path'
    - fstype: fuse
    - opts: {{ mount_opts }}
    - extra_mount_invisible_keys: {{ fuse_and_ssh_opts }}
    - mkmnt: true
    - persist: true

Steps to Reproduce the behavior
Attempt 1: Change device and apply the state

# salt-call state.apply
local:
----------
          ID: /mnt/test
    Function: mount.mounted
      Result: True
     Comment: Target was successfully mounted. Added new entry to the fstab.
     Started: 08:27:58.714180
    Duration: 102.657 ms
     Changes:
              ----------
              mount:
                  True
              persist:
                  new
              umount:
                  Forced unmount because devices don't match. Wanted: sshfs#me@host:/path2 (me@host:/path2), current: me@host:/path

Summary for local
--------------
Succeeded: 163 (changed=1)
Failed:      0
--------------
Total states run:     163
Total run time:    18.415 s

# grep /mnt/test /etc/fstab
sshfs#me@host:/path     /mnt/test    fuse    OPTS...
sshfs#me@host:/path2    /mnt/test    fuse    OPTS...

Attempt 2: Apply a mount.fstab_absent state:

# salt-call state.single mount.fstab_absent name=foo fs_file=/mnt/test
local:
----------
          ID: foo
    Function: mount.fstab_absent
      Result: True
     Comment: /mnt/test entry removed from /etc/fstab.
     Started: 08:41:51.302527
    Duration: 2.983 ms
     Changes:
              ----------
              persist:
                  removed

Summary for local
------------
Succeeded: 1 (changed=1)
Failed:    0
------------
Total states run:     1
Total run time:   2.983 ms

# grep /mnt/test /etc/fstab
sshfs#me@host:/path     /mnt/test    fuse    OPTS...
sshfs#me@host:/path2    /mnt/test    fuse    OPTS...

Expected behavior
mount.mounted should ensure previous fstab entry is removed when making changes.

mount.fstab_absent should delete entries by target, and should not report changes when there were none

Versions Report

Salt Version:
          Salt: 3003.3

Dependency Versions:
          cffi: 1.14.5
      cherrypy: Not Installed
      dateutil: 2.7.3
     docker-py: Not Installed
         gitdb: Not Installed
     gitpython: Not Installed
        Jinja2: 2.10.1
       libgit2: 1.1.0
      M2Crypto: 0.31.0
          Mako: Not Installed
       msgpack: 0.6.2
  msgpack-pure: Not Installed
  mysql-python: Not Installed
     pycparser: 2.20
      pycrypto: Not Installed
  pycryptodome: 3.6.1
        pygit2: 1.6.1
        Python: 3.8.10 (default, Jun  2 2021, 10:49:15)
  python-gnupg: 0.4.5
        PyYAML: 5.3.1
         PyZMQ: 18.1.1
         smmap: Not Installed
       timelib: Not Installed
       Tornado: 4.5.3
           ZMQ: 4.3.2

System Versions:
          dist: ubuntu 20.04 focal
        locale: utf-8
       machine: x86_64
       release: 5.4.0-86-generic
        system: Linux
       version: Ubuntu 20.04 focal

Workaround

fix issue:
  cmd.run:
    - name: "sed -i '\\|/mnt/test|d' /etc/fstab"
    - prereq:
      - mount: /mnt/test

Start with the mount.mounted and mount.fstab_absent state entry points, reproducing both reported cases against /etc/fstab. Done means changing a device removes the prior target entry, fstab_absent removes all entries for the target, and a missing target reports no change; add regression coverage for both behaviors.