ci: Update the Fedora image to Fedora 36

Also remove systemtap from the image, since
we don't need it.

The v36 image is still used in gtk-4-6.

.gitlab-ci.yml

@@ -25,7 +25,7 @@ variables:
   BACKEND_FLAGS: "-Dx11-backend=true -Dwayland-backend=true -Dbroadway-backend=true"
   FEATURE_FLAGS: "-Dvulkan=enabled -Dcloudproviders=enabled"
   MESON_TEST_TIMEOUT_MULTIPLIER: 3
-  FEDORA_IMAGE: "registry.gitlab.gnome.org/gnome/gtk/fedora:v36"
+  FEDORA_IMAGE: "registry.gitlab.gnome.org/gnome/gtk/fedora:v38"
   FLATPAK_IMAGE: "registry.gitlab.gnome.org/gnome/gnome-runtime-images/gnome:master"
 
 .only-default:

.gitlab-ci/README.md

@@ -14,6 +14,9 @@ Each Docker image has a tag composed of two parts:
 See the [container registry][registry] for the available images for each
 branch, as well as their available versions.
 
+Note that using `latest` as version number will overwrite the most
+recently uploaded image in the registry.
+
 ### Checklist for Updating a CI image
 
  - [ ] Update the `${image}.Dockerfile` file with the dependencies

.gitlab-ci/fedora.Dockerfile

@@ -1,4 +1,4 @@
-FROM fedora:34
+FROM fedora:36
 
 RUN dnf -y install \
     adwaita-icon-theme \
@@ -87,7 +87,6 @@ RUN dnf -y install \
     python3-wheel \
     redhat-rpm-config \
     sassc \
-    systemtap-sdt-devel \
     vulkan-devel \
     wayland-devel \
     wayland-protocols-devel \