chore(deps): update containernetworking/v2/azure-cns docker tag to v1.8.12 - #9215

=== RUN   Test_Ubuntu2204_CSE_CachedPerformance/Task_configureKubeletAndKubectl
    cse_timing.go:342: task AKS.CSE.configureKubeletAndKubectl duration: 27.44s (threshold: 27s)
    cse_timing.go:346: CSE task AKS.CSE.configureKubeletAndKubectl took 27.44s, exceeds threshold 27s
--- FAIL: Test_Ubuntu2204_CSE_CachedPerformance/Task_configureKubeletAndKubectl (0.00s)

=== RUN   Test_Ubuntu2204_CSE_CachedPerformance
=== PAUSE Test_Ubuntu2204_CSE_CachedPerformance
=== CONT  Test_Ubuntu2204_CSE_CachedPerformance
    test_helpers.go:412: [0.000s] TAGS {Name:Test_Ubuntu2204_CSE_CachedPerformance ImageName:2204gen2containerd OS:ubuntu Arch:amd64 NetworkIsolated:false NonAnonymousACR:false GPU:false WASM:false Kata:false BootstrapTokenFallback:false KubeletCustomConfig:false Scriptless:false VHDCaching:false MockAzureChinaCloud:false RCV1PCertMode:false VMSeriesCoverageTest:false}
    test_helpers.go:222: [0.000s] → running scenario...
    test_helpers.go:239: [0.000s] using cluster abe2e-kubenet-v5-150ee in rg=abe2e-westus3 sub=8ecadfc9-d1a3-4ea4-b844-0d9f87e4d7c8
    test_helpers.go:240: [0.000s] portal: https://portal.azure.com/#@microsoft.onmicrosoft.com/resource/subscriptions/8ecadfc9-d1a3-4ea4-b844-0d9f87e4d7c8/resourceGroups/abe2e-westus3/providers/Microsoft.ContainerService/managedClusters/abe2e-kubenet-v5-150ee/overview
    test_helpers.go:272: [0.004s] → preparing AKS node...
    vmss.go:369: [0.004s] → creating VMSS rscg-2026-08-15-ubuntu2204csecachedperformance...
    vmss.go:263: [2.421s] VMSS portal link: https://ms.portal.azure.com/#@microsoft.onmicrosoft.com/resource/subscriptions/8ecadfc9-d1a3-4ea4-b844-0d9f87e4d7c8/resourceGroups/MC_abe2e-westus3_abe2e-kubenet-v5-150ee_westus3/providers/Microsoft.Compute/virtualMachineScaleSets/rscg-2026-08-15-ubuntu2204csecachedperformance/overview
    vmss.go:269: [2.422s] Managed cluster portal link: https://ms.portal.azure.com/#@microsoft.onmicrosoft.com/resource/subscriptions/8ecadfc9-d1a3-4ea4-b844-0d9f87e4d7c8/resourceGroups/MC_abe2e-westus3_abe2e-kubenet-v5-150ee_westus3/providers/Microsoft.ContainerService/managedClusters/abe2e-kubenet-v5-150ee/overview
    vmss.go:401: [21.792s] VM will be automatically deleted after the test finishes, to preserve it for debugging purposes set KEEP_VMSS=true or pause the test with a breakpoint before the test finishes or failed
    vmss.go:405: [21.792s] SSH Instructions: (may take a few minutes for the VM to be ready for SSH)
        ========================
        az network bastion ssh --target-resource-id "/subscriptions/8ecadfc9-d1a3-4ea4-b844-0d9f87e4d7c8/resourceGroups/MC_abe2e-westus3_abe2e-kubenet-v5-150ee_westus3/providers/Microsoft.Compute/virtualMachineScaleSets/rscg-2026-08-15-ubuntu2204csecachedperformance/virtualMachines/0" --name "abe2e-shared-bastion" --resource-group abe2e-westus3 --auth-type ssh-key --username azureuser --ssh-key /tmp/private-key-4286353361
        
    vmss.go:463: [123.624s] VMSS rscg-2026-08-15-ubuntu2204csecachedperformance (id: /subscriptions/8ecadfc9-d1a3-4ea4-b844-0d9f87e4d7c8/resourceGroups/MC_abe2e-westus3_abe2e-kubenet-v5-150ee_westus3/providers/Microsoft.Compute/virtualMachineScaleSets/rscg-2026-08-15-ubuntu2204csecachedperformance) tags after creation (4):
    vmss.go:480: [123.624s]   tag: ShouldEnforceKubePMCInstall = true
    vmss.go:480: [123.624s]   tag: buildID = local
    vmss.go:480: [123.624s]   tag: owner = 4cac0ed4-fd59-4da6-b9a5-d4bc46bbbb14
    vmss.go:477: [123.624s]   tag: platformsettings.host_environment.service.platform_optedin_for_rootcerts = true [RCV1P opt-in tag — platform-injected]
    bastionssh.go:304: [123.626s] Attempt 1/5 establishing SSH over bastion to 10.220.112.100
    vmss.go:510: [125.172s] VM reached running state
    vmss.go:463: [125.172s] VM instance 0 (id: /subscriptions/8ecadfc9-d1a3-4ea4-b844-0d9f87e4d7c8/resourceGroups/MC_abe2e-westus3_abe2e-kubenet-v5-150ee_westus3/providers/Microsoft.Compute/virtualMachineScaleSets/rscg-2026-08-15-ubuntu2204csecachedperformance/virtualMachines/0) tags after running (4):
    vmss.go:480: [125.172s]   tag: buildID = local
    vmss.go:480: [125.172s]   tag: owner = 4cac0ed4-fd59-4da6-b9a5-d4bc46bbbb14
    vmss.go:
... [The stack trace has been truncated as it exceeded the maximum allowed size. Please refer to the complete log available in the Test Run attachments for full details.]