update C++

Author: aignas

.bazelci/presubmit.yml

@@ -107,10 +107,10 @@ tasks:
     working_directory: examples/bzlmod
     bazel: ${{ bazel }}
     test_flags:
+      # Minimum bazel supported C++
       - "--keep_going"
-        # Without these cxxopts, BCR's Mac builds fail
-      - '--cxxopt=-std=c++14'
-      - '--host_cxxopt=-std=c++14'
+      - '--cxxopt=-std=c++17'
+      - '--host_cxxopt=-std=c++17'
     build_targets:
       - "//..."
     test_targets:

.bcr/presubmit.yml

@@ -23,10 +23,10 @@ bcr_test_module:
       platform: ${{ platform }}
       bazel: ${{ bazel }}
       test_flags:
+        # Minimum bazel supported C++
         - "--keep_going"
-          # Without these cxxopts, BCR's Mac builds fail
-        - '--cxxopt=-std=c++14'
-        - '--host_cxxopt=-std=c++14'
+        - '--cxxopt=-std=c++17'
+        - '--host_cxxopt=-std=c++17'
       build_targets:
         - "//..."
       test_targets: