chore: Cache custom golangci-lint binaries in GHA workflow

.custom-gcl.yml

@@ -1,7 +1,7 @@
-version: v2.10.1 # should be in sync with script/setup-custom-gcl.sh
+version: v2.10.1 # this is the version of golangci-lint
 plugins:
   - module: "github.com/google/go-github/v84/tools/extraneousnew"
-    path: ./tools/extraneous-new
+    path: ./tools/extraneousnew
   - module: "github.com/google/go-github/v84/tools/fmtpercentv"
     path: ./tools/fmtpercentv
   - module: "github.com/google/go-github/v84/tools/sliceofpointers"

.github/workflows/linter.yml

@@ -13,6 +13,12 @@ jobs:
       with:
         go-version: stable
         cache-dependency-path: "**/go.sum"
+    - uses: actions/cache@668228422ae6a00e4ad889ee87cd7109ec5666a7 # v5.0.4
+      with:
+        path: |
+          bin/golangci-lint
+          bin/custom-gcl
+        key: ${{ runner.os }}-${{ runner.arch }}-tools-${{ hashFiles('.custom-gcl.yml', 'tools/**/go.mod', 'tools/**/go.sum', 'tools/**/*.go') }}
     - run: script/lint.sh
       env:
         CHECK_GITHUB_OPENAPI: 1

script/setup-custom-gcl.sh

@@ -4,11 +4,19 @@
 
 set -e
 
-# should be in sync with .custom-gcl.yml
-GOLANGCI_LINT_VERSION="v2.10.1"
+ROOT_DIR="$(cd -- "$(dirname -- "$0")/.." > /dev/null 2>&1 && pwd -P)"
+CUSTOM_GCL_CONFIG="$ROOT_DIR/.custom-gcl.yml"
+GOLANGCI_LINT_VERSION="$(
+  sed -n 's/^[[:space:]]*version:[[:space:]]*//p' "$CUSTOM_GCL_CONFIG" \
+  | sed '1{s/[[:space:]]*#.*$//;s/^"//;s/"$//;s/[[:space:]]*$//;p;};d'
+)"
 
-# should in sync with fmt.sh and lint.sh
-BIN="$(pwd -P)"/bin
+if [ -z "$GOLANGCI_LINT_VERSION" ]; then
+  echo "Error: could not determine golangci-lint version from $CUSTOM_GCL_CONFIG" >&2
+  exit 1
+fi
+
+BIN="$ROOT_DIR/bin"
 
 mkdir -p "$BIN"