Packit+TMT: Fix copr repo enablement on upstream CentOS Stream tests

The previous `adjust` conditionals ended up skipping copr repo and
package upgrade steps for CentOS Stream environments.

This should be resolved by directly using `prepare` and `when` keywords
for setting conditions.

Signed-off-by: Lokesh Mandvekar <[email protected]>

plans/main.fmf

@@ -2,26 +2,23 @@ discover:
     how: fmf
 execute:
     how: tmt
-adjust:
-    - when: initiator == packit
-      because: "We need to test with updated packages from rhcontainerbot/podman-next copr"
-      prepare+:
-        how: shell
-        script: |
-            sed -i -n '/^priority=/!p;$apriority=1' /etc/yum.repos.d/*podman-next*.repo
-            dnf -y upgrade --allowerasing
-    # FIXME: Use epel10 once bats is available there
-    - when: distro == centos-stream-10 or distro == rhel-10
-      because: "bats isn't yet available on epel10"
-      prepare+:
-        how: install
-        copr: rhcontainerbot/bats-el10
-        package: bats
-    - when: distro == centos-stream-9 or distro == rhel-9
-      because: "bats is present on EPEL on rhel9 / c9s"
-      prepare+:
-        how: feature
-        epel: enabled
+prepare:
+    - name: "Upgrade with podman-next enabled"
+      how: shell
+      script: |
+        sed -i -n '/^priority=/!p;$apriority=1' /etc/yum.repos.d/*podman-next*.repo
+        dnf -y upgrade --allowerasing
+      when: initiator == packit
+    - name: "Enable EPEL on RHEL for bats and other packages"
+      how: shell
+      script: |
+        dnf -y install 'dnf-command(config-manager)'
+        dnf config-manager --set-enabled epel
+      when: distro != fedora
+    - name: "Enable bats on rhel10"
+      how: shell
+      script: dnf -y copr enable rhcontainerbot/bats-el10
+      when: distro != fedora && distro != centos-stream-9 && distro != rhel-9
 
 /upstream:
     summary: Run crun specific Podman system tests on upstream PRs