Use std::format instead of fmtlib in spdlog

[yanavlasov]

Additional Description: First step in replacing fmtlib with its std::format equivalent. C++20 std::format does not support formatting of iterative types and a few places needed absl::StrJoin as a workaround.

Risk Level: Low Testing: Unit Tests Docs Changes: N/A Release Notes: N/A Platform Specific Features: N/A

[repokitteh-read-only[bot]]

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:cat:

Caused by: https://github.com/envoyproxy/envoy/pull/39550 was opened by yanavlasov.

see: more, trace.

[github-actions[bot]]

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