simplify: remove redundant loop-variable copies in eventgateway files

[Copilot]

In Go 1.22+, each range-loop iteration owns its variable, making xCopy := x; return &xCopy dead code. Six functions across the eventgateway and adopt packages used this pattern unnecessarily.

Changes

• findClusterByName (backend_clusters.go) — 2 copies removed
• findVirtualClusterByName (virtual_clusters.go) — 2 copies removed
• findListenerByName (listeners.go) — 1 copy removed
• findDataPlaneCertByName (data_plane_certificates.go) — 1 copy removed
• findClusterPolicyByName (cluster-policies.go) — 1 copy removed
• resolveEventGatewayControlPlane (adopt/event_gateway.go) — 1 copy removed

Before:

for _, cluster := range clusters {
    if cluster.Name != "" && strings.ToLower(cluster.Name) == lowered {
        clusterCopy := cluster
        return &clusterCopy
    }
}

After:

for _, cluster := range clusters {
    if cluster.Name != "" && strings.ToLower(cluster.Name) == lowered {
        return &cluster
    }
}

No functional change — aligns with the Go 1.26 modernization standard in AGENTS.md.

[Copilot]

Pull request overview

This PR modernizes several Event Gateway and adopt helper functions by removing now-unnecessary per-iteration struct copies when returning pointers from range loops, aligning the code with the repository’s Go 1.26 toolchain semantics.

Changes:

• Removed redundant xCopy := x patterns in multiple find*ByName helpers and in resolveEventGatewayControlPlane.
• Continued to return pointers to per-iteration range variables (maintaining the prior “pointer to copy” behavior without extra locals).

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
internal/cmd/root/products/konnect/eventgateway/backend_clusters.go	Removes redundant loop-variable copy in backend cluster lookup helper.
internal/cmd/root/products/konnect/eventgateway/virtual_clusters.go	Removes redundant loop-variable copies in virtual cluster lookup helper.
internal/cmd/root/products/konnect/eventgateway/listeners.go	Removes redundant loop-variable copy in listener lookup helper.
internal/cmd/root/products/konnect/eventgateway/data_plane_certificates.go	Removes redundant loop-variable copy in data plane certificate lookup helper.
internal/cmd/root/products/konnect/eventgateway/cluster-policies.go	Removes redundant loop-variable copy in cluster policy lookup helper.
internal/cmd/root/products/konnect/adopt/event_gateway.go	Removes redundant loop-variable copy when selecting an EGW control plane by name.