chore: Fix undeclared class properties in integration tests

[ChristophWurst]

PHPUnit output is hard to read otherwise.

[ChristophWurst]

/backport to stable3.4

[backportbot-nextcloud]

The backport to stable3.4 failed. Please do this backport manually.

# Switch to the target branch and update it
git checkout stable3.4
git pull origin stable3.4

# Create the new backport branch
git checkout -b fix/foo-stable3.4

# Cherry pick the change from the commit sha1 of the change against the default branch
# This might cause conflicts. Resolve them.
git cherry-pick abc123

# Push the cherry pick commit to the remote repository and open a pull request
git push origin fix/foo-stable3.4

More info at https://docs.nextcloud.com/server/latest/developer_manual/getting_started/development_process.html#manual-backport

[ChristophWurst]

/backport to stable3.4

[ChristophWurst]

/backport to stable3.4