fix(ibmcloud): remove nonexistent /opt/dotnet from ppc64le snippet

On RHEL 9/ppc64le, dotnet installs to /usr/lib64/dotnet via dnf, not
/opt/dotnet. The GH runner is self-contained (uses ./bin/Runner.Listener)
and does not need DOTNET_ROOT. The chown on /opt/dotnet caused cloud-init
to fail after a successful build.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: deekay2310

pkg/integrations/github/snippet-linux-ppc64le.sh

@@ -97,12 +97,10 @@ if [ ! -f /opt/runner-cache/config.sh ]; then
 fi
 
 id -u runner &>/dev/null || useradd -m -s /bin/bash runner
-chown -R runner:runner /opt/runner-cache /opt/dotnet
+chown -R runner:runner /opt/runner-cache
 
 sudo -u runner bash -c '
     cd /opt/runner-cache
-    export DOTNET_ROOT=/opt/dotnet
-    export PATH=$PATH:$DOTNET_ROOT
 
     ./config.sh \
         --unattended \