meson: change const& style and reformat with clang-format

1 job for master in 60 minutes and 1 second (queued for 60 minutes and 4 seconds)
Status Job ID Name Coverage
  Build
failed #12697
linux kf5-qt5 qt5.12

01:00:01

 
Name Stage Failure
failed
linux kf5-qt5 qt5.12 Build The script exceeded the maximum execution time set for the job
kf5.kio.core: "/home/jenkins/install-prefix/lib64/plugins/kf5/kio/trash.so" supports protocols ("trash")
kf5.kio.core: "/home/jenkins/install-prefix/lib64/plugins/kf5/kio/file.so" supports protocols ("file")
kf5.kio.core: "/home/jenkins/install-prefix/lib64/plugins/kf5/kio/ghelp.so" supports protocols ("ghelp")
kf5.kio.core: "/home/jenkins/install-prefix/lib64/plugins/kf5/kio/ftp.so" supports protocols ("ftp")
kf5.kio.core: "/home/jenkins/install-prefix/lib64/plugins/kf5/kio/http.so" supports protocols ("http", "https", "webdav", "webdavs")
kf5.kio.core: "/home/jenkins/install-prefix/lib64/plugins/kf5/kio/help.so" supports protocols ("help")
kf5.kio.core: "/home/jenkins/install-prefix/lib64/plugins/kf5/kio/remote.so" supports protocols ("remote")
Pulling docker image gitlab/gitlab-runner-helper:x86_64-ac2a293c ...
ERROR: Job failed: execution took longer than 1h0m0s seconds