feat: add dev toolchain setup script

Add toolchain.sh script to install and configure development dependencies

hack/toolchain.sh

@@ -0,0 +1,25 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+K8S_VERSION="${K8S_VERSION:="1.29.x"}"
+KUBEBUILDER_ASSETS="/usr/local/kubebuilder/bin"
+
+main() {
+    tools
+    kubebuilder
+}
+
+tools() {
+    if ! echo "$PATH" | grep -q "${GOPATH:-undefined}/bin\|$HOME/go/bin"; then
+        echo "Go workspace's \"bin\" directory is not in PATH. Run 'export PATH=\"\$PATH:\${GOPATH:-\$HOME/go}/bin\"'."
+    fi
+
+    go install github.com/awslabs/attribution-gen@latest
+    go install github.com/golangci/golangci-lint/cmd/golangci-lint@latest
+    go install github.com/google/ko@latest
+    go install github.com/mikefarah/yq/v4@latest
+    go install sigs.k8s.io/controller-runtime/tools/setup-envtest@latest
+    go install sigs.k8s.io/controller-tools/cmd/controller-gen@latest
+    go install github.com/sigstore/cosign/v2/cmd/cosign@latest
+    go install golang.org/x/vuln/cmd/govulncheck@latest
+}