fix updating cached mounts with multiple entries for root id

[icewind1991]

• Also filter for mount_point_hash
• We don't need to update the mount_point since if that changes they won't be counted as "changed mounts"

[icewind1991]

/backport to stable33

[icewind1991]

/backport to stable32

[icewind1991]

This wasn't noticed earlier because the invalid entries would have been automatically repaired in the next setup.

However #56933 added an index that makes case this throw an error

[backportbot]

The backport to stable32 failed. Please do this backport manually.

# Switch to the target branch and update it
git checkout stable32
git pull origin stable32

# Create the new backport branch
git checkout -b backport/58727/stable32

# Cherry pick the change from the commit sha1 of the change against the default branch
# This might cause conflicts, resolve them
git cherry-pick d14c4082 9884dec6

# Push the cherry pick commit to the remote repository and open a pull request
git push origin backport/58727/stable32

Error: Failed to push branch backport/58727/stable32: remote: Invalid username or token. Password authentication is not supported for Git operations.
fatal: Authentication failed for 'https://github.com/nextcloud/server.git/'

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Learn more about backports at https://docs.nextcloud.com/server/stable/go.php?to=developer-backports.