Fix VRS OSS macOS build: include <fmt/format.h> for fmt::format

[YLouWashU]

Summary:
The VRS OSS GitHub CI (Build VRS on macos-latest, both XPRS=OFF and XPRS=ON) fails to compile with:

error: no member named 'format' in namespace 'fmt'

at every translation unit that uses the logging / check macros (first vrs/helpers/Throttler.cpp → XR_LOGW, then vrs/DataSource.cpp → XR_DEV_CHECK_GT, etc.).

The logging headers define their macros in terms of fmt::format(...) but only include <fmt/core.h>. fmt::format is declared in <fmt/format.h>. This compiled before only because older {fmt} releases happened to pull format in transitively via core.h. Homebrew on macos-latest recently upgraded {fmt} to 11.x, where the headers were reorganized (core.h is now a deprecated shim and no longer drags in the format definition), so the symbol is no longer visible. This is environment-driven — no VRS source change triggered it — which is why a previously-green build started failing this week, and why it is independent of the XPRS flag (both matrix legs break identically).

Switch the include to <fmt/format.h> (which transitively includes core.h/base.h) in every VRS OSS file that calls fmt::format but only included <fmt/core.h>:

• vrs/oss/logging/Log.h
• vrs/oss/logging/Checks.h
• vrs/oss/logging/Verify.h
• vrs/utils/cli/CompressionBenchmark.cpp

This makes each header/TU self-contained against the function it actually calls, independent of the {fmt} version.

Differential Revision: D109906400

[meta-codesync]

@YLouWashU has exported this pull request. If you are a Meta employee, you can view the originating Diff in D109906400.