ci: Bump actions/checkout to v3

This fixes an issue reported on
actions/checkout#760.

Signed-off-by: Gustavo Henrique Nihei <gustavo.nihei@espressif.com>

.github/workflows/build.yml

@@ -13,7 +13,7 @@ jobs:
       matrix:
         targets: [esp32, esp32s2, esp32s3, esp32c3]
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - name: Build IDF bootloader and partition table
         uses: docker://docker.io/espressif/idf:v4.4.1
         with:
@@ -29,7 +29,9 @@ jobs:
       matrix:
         targets: [esp32, esp32s2, esp32c3]
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
+        with:
+          set-safe-directory: /github/workspace
       - name: Build MCUboot bootloader
         uses: docker://docker.io/espressif/idf:release-v4.4
         with: