gha/conformance-clustermesh: let service nodeport be selected randomly

Do not hardcode the nodeport assigned to the clustermesh-apiserver
service, and instead let it be assigned randomly upon creation. This
prevents the possibility of hitting a conflict with the port assigned
to other services, which happens from time to time causing flakiness.
The original reason for hardcoding the port no longer holds since
cilium#24692 got fixed by [1].

[1]: 12acdb5 ("bpf/socklb: Don't resolve remote cluster NodePort services")

Signed-off-by: Marco Iorio <marco.iorio@isovalent.com>

Author: giorio94

.github/workflows/conformance-clustermesh.yaml

@@ -566,13 +566,12 @@ jobs:
         env:
           KVSTORE_ID: 1
         run: |
-          # Explicitly configure the NodePort to make sure that it is different in
-          # each cluster, to workaround #24692
+          # Let the NodePort to be selected randomly, to prevent the risk of conflicts.
           cilium --context ${{ env.contextName1 }} install \
             ${{ steps.vars.outputs.cilium_install_defaults }} \
             --helm-set cluster.name=${{ env.ciliumClusterName1 }} \
             --helm-set cluster.id=1 \
-            --helm-set clustermesh.apiserver.service.nodePort=32379 \
+            --helm-set clustermesh.apiserver.service.nodePort=0 \
             --helm-set clustermesh.apiserver.tls.authMode=${{ matrix.cm-auth-mode-1 }} \
             ${{ steps.vars.outputs.cilium_install_multipool_ipam_cluster1 }} \
             ${{ steps.kvstore.outputs.cilium_install_kvstore }} \
@@ -589,13 +588,12 @@ jobs:
         env:
           KVSTORE_ID: 2
         run: |
-          # Explicitly configure the NodePort to make sure that it is different in
-          # each cluster, to workaround #24692
+          # Let the NodePort to be selected randomly, to prevent the risk of conflicts.
           cilium --context ${{ env.contextName2 }} install \
             ${{ steps.vars.outputs.cilium_install_defaults }} \
             --helm-set cluster.name=${{ env.ciliumClusterName2 }} \
             --helm-set cluster.id=${{ matrix.maxConnectedClusters }} \
-            --helm-set clustermesh.apiserver.service.nodePort=32380 \
+            --helm-set clustermesh.apiserver.service.nodePort=0 \
             --helm-set clustermesh.apiserver.tls.authMode=${{ matrix.cm-auth-mode-2 }} \
             ${{ steps.vars.outputs.cilium_install_multipool_ipam_cluster2 }} \
             ${{ steps.kvstore.outputs.cilium_install_kvstore }} \