Update actions/checkout action to v4 (#2225)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

.github/workflows/generate-changelog.yml

diff --git a/.github/workflows/generate-changelog.yml b/.github/workflows/generate-changelog.yml
index ca91213..e0c081b 100644
--- a/.github/workflows/generate-changelog.yml
+++ b/.github/workflows/generate-changelog.yml
@@ -7,7 +7,7 @@
     runs-on: ubuntu-latest
     if: github.repository == 'pinterest/ktlint'
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac # v4
         with:
           fetch-depth: 0 # fetch all commits/branches/tags
 

.github/workflows/gradle-wrapper-validation.yml

diff --git a/.github/workflows/gradle-wrapper-validation.yml b/.github/workflows/gradle-wrapper-validation.yml
index 2b7cca2..f23cb03 100644
--- a/.github/workflows/gradle-wrapper-validation.yml
+++ b/.github/workflows/gradle-wrapper-validation.yml
@@ -7,5 +7,5 @@
     name: "Validation"
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac # v4
       - uses: gradle/wrapper-validation-action@v1

.github/workflows/publish-release-build.yml

diff --git a/.github/workflows/publish-release-build.yml b/.github/workflows/publish-release-build.yml
index 6868a74..2bccd1d 100644
--- a/.github/workflows/publish-release-build.yml
+++ b/.github/workflows/publish-release-build.yml
@@ -11,7 +11,7 @@
     if: github.repository == 'pinterest/ktlint'
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac # v4
         with:
           ref: 'master'
 

.github/workflows/publish-release-docs.yml

diff --git a/.github/workflows/publish-release-docs.yml b/.github/workflows/publish-release-docs.yml
index 3f97b19..a8b31e7 100644
--- a/.github/workflows/publish-release-docs.yml
+++ b/.github/workflows/publish-release-docs.yml
@@ -10,7 +10,7 @@
     runs-on: ubuntu-latest
     if: github.repository == 'pinterest/ktlint'
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac # v4
         with:
           fetch-depth: 0 # fetch all commits/branches
       - uses: actions/setup-python@v4

.github/workflows/publish-snapshot-build.yml

diff --git a/.github/workflows/publish-snapshot-build.yml b/.github/workflows/publish-snapshot-build.yml
index 6c6cb80..8e70b34 100644
--- a/.github/workflows/publish-snapshot-build.yml
+++ b/.github/workflows/publish-snapshot-build.yml
@@ -14,7 +14,7 @@
     runs-on: ubuntu-latest
     if: github.repository == 'pinterest/ktlint'
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac # v4
 
       - uses: ./.github/actions/setup-gradle-build
 

.github/workflows/publish-snapshot-docs.yml

diff --git a/.github/workflows/publish-snapshot-docs.yml b/.github/workflows/publish-snapshot-docs.yml
index 4c376dd..1e29e0e 100644
--- a/.github/workflows/publish-snapshot-docs.yml
+++ b/.github/workflows/publish-snapshot-docs.yml
@@ -10,7 +10,7 @@
     runs-on: ubuntu-latest
     if: github.repository == 'pinterest/ktlint'
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac # v4
         with:
           fetch-depth: 0 # fetch all commits/branches
       - uses: actions/setup-python@v4

.github/workflows/pull-request-with-code.yml

diff --git a/.github/workflows/pull-request-with-code.yml b/.github/workflows/pull-request-with-code.yml
index 7a8be89..d7090c4 100644
--- a/.github/workflows/pull-request-with-code.yml
+++ b/.github/workflows/pull-request-with-code.yml
@@ -36,7 +36,7 @@
     runs-on: ${{ matrix.os }}
     name: "[build] OS=${{ matrix.os }} Kotlin=stable"
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac # v4
 
       - uses: ./.github/actions/setup-gradle-build
 
@@ -71,7 +71,7 @@
     runs-on: ${{ matrix.os }}
     name: "[build] OS=${{ matrix.os }}, Kotlin=dev"
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac # v4
 
       - uses: ./.github/actions/setup-gradle-build
 
@@ -87,7 +87,7 @@
     runs-on: ${{ matrix.os }}
     name: "[tests] OS=${{ matrix.os }}, Java=${{ matrix.jdk }}"
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac # v4
 
       - uses: ./.github/actions/setup-gradle-build
         with: