ci: move some variables closer to their usage stable

ci: move some variables closer to their usage

These were defined globaly because we had trouble making them inherited. This
is now fixed, so we can get them were they belong.

--- a/contrib/heptapod-ci.yml	Fri Nov 08 14:35:57 2024 +0100
+++ b/contrib/heptapod-ci.yml	Fri Nov 08 14:44:56 2024 +0100
@@ -32,8 +32,6 @@
 variables:
     PYTHON: python
     HG_CI_IMAGE_TAG: "v2.1"
-    TEST_HGTESTS_ALLOW_NETIO: "0"
-    SHOW_VERSION_OF: "$PYTHON"
 
 .all:
   # help changing all job at once when debugging
@@ -81,6 +79,9 @@
 .runtests:
     extends: .all
     stage: tests
+    variables:
+      SHOW_VERSION_OF: "$PYTHON"
+      TEST_HGTESTS_ALLOW_NETIO: "0"
     # The runner made a clone as root.
     # We make a new clone owned by user used to run the step.
     before_script: