Update histogram.cc 

ci: update GitHub Actions worflows ci: use clang-format-12 (cherry picked from commit 7e1a2d8) ci: replace windows-2016 agent (cherry picked from commit 9e60f81) ci: use actions/checkout@v3 (cherry picked from commit d848720) ci: fix iwyu (cherry picked from commit 47868f9)

feat(push): Add method to delete metrics for instance Fixes: jupp0r#303

fix(core): Locale-independent floating-point serialization Fixes: jupp0r#509

Prepare v0.12.3 release 

core: avoid collecting empty metric families 

Merge pull request jupp0r#453 from jupp0r/fix-std-tochars core: Fix usage of std::to_chars

Merge pull request jupp0r#435 from jupp0r/improve-example pull: Add better example

pull: Use internal base64 decoding function to avoid dependency (jupp… …0r#417)

chore: Raise version to v0.10.0 due to changed public interface