Sync presubmit.yml with what landed in BCR

Bazel 7 defaults to C++14, and BCR doesn't pick up .bazelrc, so we need
to specify this in yet another place.

See also
bazelbuild/bazel-central-registry#3579

Change-Id: I5e639b86ec52dd9ebd14c58aa9cca7997a5f5c87
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/75407
Commit-Queue: Bob Beck <bbe@google.com>
Reviewed-by: Bob Beck <bbe@google.com>
Auto-Submit: David Benjamin <davidben@google.com>

.bcr/presubmit.yml

@@ -3,17 +3,25 @@ build_targets: &build_targets
   - "@boringssl//:ssl"
 
 matrix: &matrix
-  non_macos_platform:
+  linux_platforms:
     - debian11
     - ubuntu2204
-    - windows
   bazel: [7.x]
 tasks:
-  verify_targets:
-    name: Verify build targets
-    platform: ${{ non_macos_platform }}
+  verify_targets_on_linux:
+    name: Verify build targets on Linux
+    platform: ${{ linux_platforms }}
     bazel: ${{ bazel }}
     build_targets: *build_targets
+    build_flags:
+      - '--cxxopt=-std=c++17'
+  verify_targets_on_windows:
+    name: Verify build targets on Windows
+    platform: windows
+    bazel: ${{ bazel }}
+    build_targets: *build_targets
+    build_flags:
+      - '--cxxopt=/std:c++17'
   # Work around https://github.com/bazelbuild/bazel/issues/10472
   verify_targets_on_macos:
     name: Verify build targets on macOS
@@ -27,12 +35,22 @@ bcr_test_module:
   module_path: util/bazel-example
   matrix: *matrix
   tasks:
-    run_test_module:
-      name: Run test module
-      platform: ${{ non_macos_platform }}
+    run_test_module_on_linux:
+      name: Run test module on Linux
+      platform: ${{ linux_platforms }}
+      bazel: ${{ bazel }}
+      build_targets:
+        - //...
+      build_flags:
+        - '--cxxopt=-std=c++17'
+    run_test_module_on_windows:
+      name: Run test module on Windows
+      platform: windows
       bazel: ${{ bazel }}
       build_targets:
         - //...
+      build_flags:
+        - '--cxxopt=/std:c++17'
     # Work around https://github.com/bazelbuild/bazel/issues/10472
     run_test_module_on_macos:
       name: Run test module on macOS