ci: Update deprecated actions

Author: kiritofeng

.github/workflows/build.yml

@@ -8,7 +8,7 @@ jobs:
         python-version: [ 3.10.20, 3.11.15, 3.12.13, 3.13.12, 3.14.3 ]
         arch: [ amd64, aarch64 ]
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Setup QEMU
         if: matrix.arch != 'amd64'
         uses: docker/setup-qemu-action@v4

.github/workflows/update-versions.yml

@@ -7,9 +7,9 @@ jobs:
     if: github.repository == 'DMOJ/runtimes-python'
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - name: Set up Python 3.14
-        uses: actions/setup-python@v5
+        uses: actions/setup-python@v6
         with:
           python-version: '3.14'
       - name: Installing dependencies
@@ -18,7 +18,7 @@ jobs:
         run: |
           sed -i '/python-version:/c\        python-version: [ '"$(python get_versions.py | tr '\n' , | sed 's/,$//;s/,/, /g')"' ]' .github/workflows/build.yml
       - name: Create pull request
-        uses: peter-evans/create-pull-request@v4
+        uses: peter-evans/create-pull-request@v6
         with:
           author: dmoj-build <build@dmoj.ca>
           committer: dmoj-build <build@dmoj.ca>