Update bcr presubmit template (#95)

.bcr/presubmit.yml

diff --git a/.bcr/presubmit.yml b/.bcr/presubmit.yml
index 7c7ac8a..62198d9 100644
--- a/.bcr/presubmit.yml
+++ b/.bcr/presubmit.yml
@@ -1,10 +1,12 @@
 matrix:
   platform: ["macos", "ubuntu2004"]
+  bazel: ["7.x", "6.x"]
 
 tasks:
   verify_targets:
     name: "Verify build targets"
     platform: ${{ platform }}
+    bazel: ${{ bazel }}
     build_targets:
       - '@buildifier_prebuilt//:buildifier'
       - '@buildifier_prebuilt//:buildozer'
@@ -13,9 +15,11 @@
   module_path: ""
   matrix:
     platform: ["macos", "ubuntu2004"]
+    bazel: ["7.x", "6.x"]
   tasks:
     run_test_module:
       name: "Run test module"
       platform: ${{ platform }}
+      bazel: ${{ bazel }}
       test_targets:
         - '//tests:all'