fix(storage): no workaround needed with libc++ and MSVC

[coryan]

Thanks to @brianpl for this patch

This change is 

[google-cloud-cpp-bot]

Google Cloud Build Logs
For commit: 8876144aea9c29990c88d7ff6bba49d06788d5b2

• Public Access Build Logs
• Cloud Build Console (requires auth)
• Kokoro Logs (requires auth)

ℹ️ NOTE: Kokoro logs are linked from "Details" below.

[codecov]

Codecov Report

Merging #9768 (8876144) into main (56416e2) will increase coverage by 0.00%.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main    #9768   +/-   ##
=======================================
  Coverage   94.22%   94.22%           
=======================================
  Files        1495     1495           
  Lines      139465   139465           
=======================================
+ Hits       131411   131414    +3     
+ Misses       8054     8051    -3     

Impacted Files	Coverage Δ
.../cloud/storage/internal/policy_document_request.cc	98.05% <ø> (ø)
...e/cloud/pubsublite/internal/alarm_registry_impl.cc	97.05% <0.00%> (-2.95%)	⬇️
...cloud/pubsub/internal/subscription_session_test.cc	97.98% <0.00%> (-1.35%)	⬇️
...bigtable/examples/bigtable_hello_instance_admin.cc	83.00% <0.00%> (+2.00%)	⬆️
...loud/spanner/internal/logging_result_set_reader.cc	92.00% <0.00%> (+4.00%)	⬆️
...te/integration_tests/publisher_integration_test.cc	98.68% <0.00%> (+6.57%)	⬆️
...e/cloud/spanner/testing/cleanup_stale_instances.cc	72.22% <0.00%> (+11.11%)	⬆️

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.