gitlab-ci: declare that Linux 3.17 is needed

Fedora's Qt builds use syscalls added in Linux 3.17, so the CI host
needs at least that new of a kernel in order to run these jobs.

.gitlab-ci.yml

@@ -86,7 +86,7 @@ build:fedora33-shared-debug-mpi-python-qt:
     extends:
         - .fedora33_shared_debug_mpi_python_qt
         - .cmake_build_linux
-        - .linux_builder_tags
+        - .linux_qt_builder_tags
         - .cmake_build_artifacts
         - .run_manually
 
@@ -94,7 +94,7 @@ test:fedora33-shared-debug-mpi-python-qt:
     extends:
         - .fedora33_shared_debug_mpi_python_qt
         - .cmake_test_linux
-        - .linux_tester_tags
+        - .linux_qt_tester_tags
         - .cmake_test_artifacts
         - .run_automatically
     dependencies:

.gitlab/os-linux.yml

@@ -104,6 +104,22 @@
         - linux
         - x11
 
+.linux_qt_builder_tags:
+    tags:
+        - build
+        - docker
+        - linux
+        - linux-3.17 # needed to run Qt binaries from Fedora 33
+        - paraview
+
+.linux_qt_tester_tags:
+    tags:
+        - docker
+        - paraview
+        - linux
+        - linux-3.17
+        - x11
+
 ## Linux-specific scripts
 
 .before_script_linux: &before_script_linux