test(bootc): use dnf download for Copr install to handle NEVR mismatch

dnf reinstall --from-repo requires the exact same NEVR in the target
repo, which fails when the base image ships a different Release than
the Copr snapshot build. dnf install --from-repo won't replace an
already-installed package. Switch to dnf download + local install,
matching the ostree and compose-RPM patterns.

Assisted-by: Claude (Anthropic)
Signed-off-by: Paul Whalen <pwhalen@fedoraproject.org>

Author: Paul Whalen

tests/greenboot-bootc-anaconda-iso.sh

@@ -326,7 +326,9 @@ else
 RUN (dnf install -y 'dnf5-command(copr)' || dnf install -y 'dnf-command(copr)') && \
     dnf copr enable -y packit/fedora-iot-greenboot-rs-${PR_NUMBER} ${COPR_CHROOT} && \
     dnf clean metadata && \
-    (dnf reinstall -y --from-repo='${GREENBOOT_COPR_REPO_ID}' greenboot greenboot-default-health-checks || dnf install -y --from-repo='${GREENBOOT_COPR_REPO_ID}' greenboot greenboot-default-health-checks) && \
+    dnf download --from-repo='${GREENBOOT_COPR_REPO_ID}' --destdir /tmp/copr-rpms greenboot greenboot-default-health-checks && \
+    dnf install -y /tmp/copr-rpms/*.rpm && \
+    rm -rf /tmp/copr-rpms && \
     systemctl enable greenboot-healthcheck.service
 EOF
 fi

tests/greenboot-bootc-qcow2.sh

@@ -326,7 +326,9 @@ else
 RUN (dnf install -y 'dnf5-command(copr)' || dnf install -y 'dnf-command(copr)') && \
     dnf copr enable -y packit/fedora-iot-greenboot-rs-${PR_NUMBER} ${COPR_CHROOT} && \
     dnf clean metadata && \
-    (dnf reinstall -y --from-repo='${GREENBOOT_COPR_REPO_ID}' greenboot greenboot-default-health-checks || dnf install -y --from-repo='${GREENBOOT_COPR_REPO_ID}' greenboot greenboot-default-health-checks) && \
+    dnf download --from-repo='${GREENBOOT_COPR_REPO_ID}' --destdir /tmp/copr-rpms greenboot greenboot-default-health-checks && \
+    dnf install -y /tmp/copr-rpms/*.rpm && \
+    rm -rf /tmp/copr-rpms && \
     systemctl enable greenboot-healthcheck.service
 EOF
 fi