Allow failure on PHP 72.

Author: drupol

.github/workflows/build.yaml

@@ -59,7 +59,7 @@ jobs:
           authToken: "${{ secrets.CACHIX_AUTH_TOKEN }}"
 
       - name: Build PHP
-        continue-on-error: if ${{ matrix.php == matrix.allow-failure }}
+        continue-on-error: ${{ matrix.php == matrix.allow-failure }}
         run: nix build .#${{ matrix.php }}
 
       - name: Build Imagick extension