CI: Bump docker/setup-buildx-action from v1 to v2

Fixes deprecation warnings from GHA.

Author: guihkx

.github/workflows/ci.yml

@@ -119,7 +119,7 @@ jobs:
 
       - name: Set up Docker Buildx
         if: runner.os == 'Linux'
-        uses: docker/setup-buildx-action@v1
+        uses: docker/setup-buildx-action@v2
 
       - name: Build xtask
         run: cargo build -p xtask

.github/workflows/weekly.yml

@@ -18,7 +18,7 @@ jobs:
       - uses: actions/checkout@v3
       - uses: ./.github/actions/setup-rust
       - name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@v1
+        uses: docker/setup-buildx-action@v2
       - name: Build xtask
         run: cargo build -p xtask
       - name: Build Docker image