Adjust konflux pipelines timeout

An update of a compose image from a specific Fedora version
triggers at least 4 builds: 'minimal', 'minimal-plus', 'standard'
and 'iot'.

We usually have 2 compose images updates (Fedora 42 and Rawhide) per
day so up to 8 builds are triggered at the same time. As we don't seem
to have a lot of resources in the Konflux cluster this leads to
build failures because of timeouts (the default pipeline timeout is 1h).

This change tries to mitigate this until we get more resources in the
Konflux cluster.

Signed-off-by: Miguel Martín <mmartinv@redhat.com>

.tekton/fedora-bootc-rawhide-iot-pull-request.yaml

@@ -53,3 +53,5 @@ spec:
     - name: kind
       value: pipeline
     resolver: bundles
+  timeouts:
+    pipeline: 6h