CI: Install more packages from PyPI

Apparently, httpx and rich are not available in RHEL+EPEL 10.

Perhaps they were installed from Fedora previously on Zuul,
due to https://issues.redhat.com/browse/TFT-2564

tests/unit/main.fmf

@@ -3,17 +3,16 @@ test: ./runtest.sh
 require:
   - cargo
   - git-core
+  - python3-idna # packaged dependency of httpx
   - python3-click
   - python3-filelock
   - python3-hatchling
-  - python3-httpx
   - python3-packaging
   - python3-pathspec
   - python3-pip
   - python3-platformdirs
   - python3-pytest
   - python3-pytest-mock
-  - python3-rich
   - python3-tomli-w
   - python3-virtualenv
 duration: 10m

tests/unit/runtest.sh

@@ -1,13 +1,12 @@
 #!/bin/bash -eux
 
-# hatchling 1.24+ requires uv and editables for testing - they're not available
+# hatchling 1.24+ requires uv and others for testing - they're not available
 # in our systems, hence PyPI installation
-# install the specific version of uv that has been released around the time
-# the tested hatchling's version was out
-# editables 0.5 has been released in July 2023, pinning it just to be sure it works
+# install the specific version of packages that have been released around the time
+# the tested hatchling's version was out, just to be sure it works
 # we don't rebase packages often in CentOS Stream, so version constraints
 # should be reasonably safe to be hardcoded
-pip install uv==0.1.35 editables==0.5
+pip install uv==0.1.35 editables==0.5 rich==13.9.4 httpx==0.27.2
 
 # Get the version of our installed component
 VERSION=$(rpm -q --queryformat="%{VERSION}" python3-hatchling)