Upgrade k8s modules and linter

.gitignore

@@ -22,3 +22,6 @@
 
 # Hugo temp file
 .hugo_build.lock
+
+# anchor
+.anchor

Dockerfile

@@ -3,8 +3,8 @@
 # Copyright 2020-2026 the Pinniped contributors. All Rights Reserved.
 # SPDX-License-Identifier: Apache-2.0
 
-ARG BUILD_IMAGE=golang:1.27.0@sha256:0ecdc2a9f6156af6451080bfe3d8382a662fcc4e209608c6f919e643453514c1
-ARG BASE_IMAGE=gcr.io/distroless/static:nonroot@sha256:1c2c046bc09ed40fad370b599a0b1ae7987f55b01e247cf27a7c27cd97e5bbc7
+ARG BUILD_IMAGE=golang:1.27.1@sha256:e0174e51e81218523251d85d248a90d24c3d5e81543b4f07a5d66229397db190
+ARG BASE_IMAGE=gcr.io/distroless/static:nonroot@sha256:e2e927ec666bae08560abb3c55d0659eceabb657f56b6782ab500a9fc7f555e3
 
 # Prepare to cross-compile by always running the build stage in the build platform, not the target platform.
 FROM --platform=$BUILDPLATFORM $BUILD_IMAGE AS build-env

cmd/pinniped/cmd/kubeconfig.go

@@ -1,4 +1,4 @@
-// Copyright 2020-2025 the Pinniped contributors. All Rights Reserved.
+// Copyright 2020-2026 the Pinniped contributors. All Rights Reserved.
 // SPDX-License-Identifier: Apache-2.0
 
 package cmd
@@ -1116,7 +1116,7 @@ func selectUpstreamIDPFlow(discoveredIDPFlows []idpdiscoveryv1alpha1.IDPFlow, se
 			}
 		}
 		return "", fmt.Errorf(
-			"no client flow %q for Supervisor upstream identity provider %q of type %q were found. "+
+			"no client flow %q for Supervisor upstream identity provider %q of type %q was found. "+
 				"Found these flows: %v",
 			specifiedFlow, selectedIDPName, selectedIDPType, discoveredIDPFlows)
 	case len(discoveredIDPFlows) == 1:

cmd/pinniped/cmd/kubeconfig_test.go

@@ -1712,7 +1712,7 @@ func TestGetKubeconfig(t *testing.T) {
 			}`),
 			wantError: true,
 			wantStderr: func(issuerCABundle string, issuerURL string) testutil.RequireErrorStringFunc {
-				return testutil.WantExactErrorString(`Error: no client flow "my-nonexistent-flow" for Supervisor upstream identity provider "some-oidc-idp" of type "oidc" were found.` +
+				return testutil.WantExactErrorString(`Error: no client flow "my-nonexistent-flow" for Supervisor upstream identity provider "some-oidc-idp" of type "oidc" was found.` +
 					` Found these flows: [non-matching-flow-1 non-matching-flow-2]` + "\n")
 			},
 		},