Revert "docs: upgrade checkout GitHub action to v5 (golangci#1272)"

This reverts commit 727cb01.

Author: eratio08

README.md

@@ -49,7 +49,7 @@ jobs:
     name: lint
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v4
       - uses: actions/setup-go@v5
         with:
           go-version: stable
@@ -87,7 +87,7 @@ jobs:
     name: lint
     runs-on: ${{ matrix.os }}
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v4
       - uses: actions/setup-go@v5
         with:
           go-version: ${{ matrix.go }}
@@ -128,7 +128,7 @@ jobs:
     outputs:
       modules: ${{ steps.set-modules.outputs.modules }}
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v4
       - uses: actions/setup-go@v5
         with:
           go-version: ${{ env.GO_VERSION }}
@@ -142,7 +142,7 @@ jobs:
       matrix:
         modules: ${{ fromJSON(needs.detect-modules.outputs.modules) }}
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v4
       - uses: actions/setup-go@v5
         with:
           go-version: ${{ env.GO_VERSION }}
@@ -209,7 +209,7 @@ jobs:
     outputs:
       modules: ${{ steps.set-modules.outputs.modules }}
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v4
       - uses: actions/setup-go@v5
         with:
           go-version: ${{ inputs.go-version }}
@@ -224,7 +224,7 @@ jobs:
       matrix:
         modules: ${{ fromJSON(needs.detect-modules.outputs.modules) }}
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v4
       - uses: actions/setup-go@v5
         with:
           go-version: ${{ inputs.go-version }}