Move remaining quay.io/cockpit/tasks references to ghcr.io

.github/workflows/tasks-container-update.yml

@@ -12,7 +12,7 @@ jobs:
       pull-requests: write
       statuses: write
     container:
-      image: quay.io/cockpit/tasks
+      image: ghcr.io/cockpit-project/tasks
       options: --user root
     steps:
       - name: Set up configuration and secrets

HACKING.md

@@ -17,7 +17,7 @@ remote, for example with
 
 ## Setting up development container
 
-The cockpit team maintains a [cockpit/tasks container](https://quay.io/repository/cockpit/tasks)
+The cockpit team maintains a [cockpit/tasks container](https://ghcr.io/cockpit-project/tasks)
 for both local development and CI. If you can install [toolbx](https://containertoolbx.org/) or
 [distrobox](https://distrobox.privatedns.org/) on your system, it is highly
 recommended to do that:

test/README.md

@@ -95,7 +95,7 @@ Pixel tests make a screenshot of a selector and compare it to a known good
 reference image. if there is a difference, the test fails and a pixel
 difference is shown.
 
-This works as our tests run in the [cockpit/tasks container](https://quay.io/repository/cockpit/tasks)
+This works as our tests run in the [cockpit/tasks container](https://ghcr.io/cockpit-project/tasks)
 which pins the browser and font rendering so repeated runs provide the same
 pixels. To generate new pixels, this tasks container must be used; your own
 browser and font rendering software might generate different results. For more