Disable failing files tag test

Fails with:

 * tests/acceptance/features/app-files-tags.feature:42
<details><summary>Show full log</summary>

```
  Scenario: add tags using the dropdown in the details view                                 # /drone/src/github.com/nextcloud/server/tests/acceptance/features/app-files-tags.feature:42
    Given I am logged in as the admin                                                       # LoginPageContext::iAmLoggedInAsTheAdmin()
    And I visit the settings page                                                           # SettingsMenuContext::iVisitTheSettingsPage()
    And I open the "Tag management" section                                                 # AppNavigationContext::iOpenTheSection()
    And I see that the button to select tags is shown                                       # SettingsContext::iSeeThatTheButtonToSelectTagsIsShown()
    And I create the tag "tag1" in the settings                                             # SettingsContext::iCreateTheTagInTheSettings()
    And I create the tag "tag2" in the settings                                             # SettingsContext::iCreateTheTagInTheSettings()
    And I create the tag "tag3" in the settings                                             # SettingsContext::iCreateTheTagInTheSettings()
    And I create the tag "tag4" in the settings                                             # SettingsContext::iCreateTheTagInTheSettings()
    And I see that the dropdown for tags in the settings eventually contains the tag "tag1" # SettingsContext::iSeeThatTheDropdownForTagsInTheSettingsEventuallyContainsTheTag()
    And I see that the dropdown for tags in the settings eventually contains the tag "tag2" # SettingsContext::iSeeThatTheDropdownForTagsInTheSettingsEventuallyContainsTheTag()
    And I see that the dropdown for tags in the settings eventually contains the tag "tag3" # SettingsContext::iSeeThatTheDropdownForTagsInTheSettingsEventuallyContainsTheTag()
    And I see that the dropdown for tags in the settings eventually contains the tag "tag4" # SettingsContext::iSeeThatTheDropdownForTagsInTheSettingsEventuallyContainsTheTag()
    And I log out                                                                           # SettingsMenuContext::iLogOut()
    And I am logged in                                                                      # LoginPageContext::iAmLoggedIn()
    And I open the details view for "welcome.txt"                                           # FileListContext::iOpenTheDetailsViewFor()
    And I open the input field for tags in the details view                                 # FilesAppContext::iOpenTheInputFieldForTagsInTheDetailsView()
    When I check the tag "tag2" in the dropdown for tags in the details view                # FilesAppContext::iCheckTheTagInTheDropdownForTagsInTheDetailsView()
    And I check the tag "tag4" in the dropdown for tags in the details view                 # FilesAppContext::iCheckTheTagInTheDropdownForTagsInTheDetailsView()
    Then I see that the tag "tag2" in the dropdown for tags in the details view is checked  # FilesAppContext::iSeeThatTheTagInTheDropdownForTagsInTheDetailsViewIsChecked()
    And I see that the tag "tag4" in the dropdown for tags in the details view is checked   # FilesAppContext::iSeeThatTheTagInTheDropdownForTagsInTheDetailsViewIsChecked()
    And I see that the input field for tags in the details view contains the tag "tag2"     # FilesAppContext::iSeeThatTheInputFieldForTagsInTheDetailsViewContainsTheTag()
      Failed asserting that false is true.
    And I see that the input field for tags in the details view contains the tag "tag4"     # FilesAppContext::iSeeThatTheInputFieldForTagsInTheDetailsViewContainsTheTag()

```
</details>

Signed-off-by: Morris Jobke <hey@morrisjobke.de>