New tests: GTK3 platform accessibility

[Stephan Bergmann]

On 8/3/23 16:37, Colomban Wendling wrote:
> Do you have an error rate value?  So I know how many successful CI runs 
> I need to suggest it did indeed improve something :)

Sorry, I at least cannot provide any useful numbers here.  I've noticed 
it both occasionally with the Jenkins builds of Gerrit patches of mine, 
and when browsing the <libreoffice-ci at global.libreoffice.org> mailing 
list (see <https://listarchives.libreoffice.org/global/libreoffice-ci/>, 
where most of the "Tinderbox on Master for Linux-DbgUtil" reported in 
the last few days are due to this issue).