Automated Release v1.2.5.6

[github-actions]

Auto-generated pull request for version 1.2.5.6.

Please use Squash and merge to include the changelog in the release message.

Changelog:

• Fix missing include in alloc.h causing compilation failure (5245) [nucleo]
• Fix failing Fedora tests. (5241) [Fabian Ruffy]
• Fix ERR/WARN_UNREACHABLE error classification (5244) [Chris Dodd]
• Deprecate Ubuntu 18.04 CI checks. (5242) [Fabian Ruffy]
• Make sure Github action workflows are correctly canceled. (5232) [Fabian Ruffy]
• Fix compile-time concatenation with negative right operand (5233) [Vladimír Štill]
• Avoid crashing compiler after a self-nested type specialization error (5236) [Vladimír Štill]
• [infra] Adding Smart caching to bazel builds (5238) [Vineet Goel]
• [bmv2] path fixes for finding BMv2 (5228) [Glen Gibb]
• improve SideEffects and StrengthReduction (5229) [Chris Dodd]
• Fixed P4C driver utility find_bin to return on first match (5226) [Pitchumani Sivanupandi]
• Try to make exename portable. Refactor searchForIncludePath. (5185) [Fabian Ruffy]
• Remove confidential & proprietary notices from Tofino testgen test programs (5189) [Andy Fingerhut]
• Replace proprietary notice and CC license on two test files with Apache-2.0 (5191) [Andy Fingerhut]
• [Tofino] Try to fix the dependency of mksizes in bf-asm CMake. (5221) [Fabian Ruffy]
• [Core] Fix namespace mismatch in irutils.h (5220) [Fabian Ruffy]
• Skip PSATernaryTest on Ubuntu 22.04 and add Black formatting (5209) [Akarsh Sahlot]
• [5211] Run before pass (5216) [Kyle Cripps]