add hack script to help update major versions of modules

hack/update-go-mod/update-majors.sh

@@ -0,0 +1,65 @@
+#!/usr/bin/env bash
+
+# Copyright 2024 the Pinniped contributors. All Rights Reserved.
+# SPDX-License-Identifier: Apache-2.0
+
+set -euo pipefail
+
+SCRIPT_DIR=$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" &>/dev/null && pwd)
+ROOT_DIR="$SCRIPT_DIR/../.."
+
+GO_MOD="${ROOT_DIR}/go.mod"
+
+modules=$(grep -v ' // indirect' "$GO_MOD" |
+  grep -v '^//' |
+  grep -v '^replace ' |
+  grep '/v[0-9]' |
+  tr -d '\t' |
+  cut -d ' ' -f 1)
+
+# Print to screen for debugging purposes.
+echo "Found current modules using major versions above v1..."
+echo "$modules"
+
+pushd "$ROOT_DIR" >/dev/null
+
+echo
+echo "Checking for new major versions..."
+for m in $modules; do
+  if [[ "$m" == "github.com/go-jose/go-jose/v3" ]]; then
+    # Skip github.com/go-jose/go-jose/v3 because we are using both v3 and v4.
+    continue
+  fi
+  next_version=$(echo "$m" | awk -F '/v' '{ printf("%s/v%d\n", $1, $2 + 1) }')
+  set +e
+  go get "${next_version}@latest"
+  found_new_version=$?
+  if [[ $found_new_version == 0 ]]; then
+    echo "Found new version $next_version. Replacing imports..."
+    find . -name './.*' -prune -o \
+      -path ./generated -prune -o \
+      -type f -name '*.go' -print0 |
+      xargs -0 sed -i '' "s#${m}#${next_version}#g"
+  fi
+  set -e
+done
+
+go mod tidy
+
+if git diff --quiet; then
+  echo
+  echo "No changes."
+else
+  echo
+  echo "Showing resulting diffs..."
+  git --no-pager diff
+
+  echo
+  echo "Running unit tests..."
+  ./hack/module.sh units
+fi
+
+popd >/dev/null
+
+echo
+echo "Done!"