examples: remove explicit arch nodeSelector

With this, it can't run on arm64 clusters...

Signed-off-by: Vincent Demeester <[email protected]>

Author: vdemeester

examples/v1/pipelineruns/beta/pipelinerun-with-matrix-and-taskrunspecs-param-substitution.yaml

@@ -8,10 +8,6 @@ spec:
     podTemplate:
       nodeSelector:
         node-type: $(params.node-type)
-  - pipelineTaskName: create-manifest-list
-    podTemplate:
-      nodeSelector:
-        kubernetes.io/arch: amd64
   pipelineSpec:
     tasks:
       - name: build-and-push-manifest