acts: new versions 31.* (spack#41733)

This adds three new versions in the 31.* series. Release notes of 31.0.0 at https://github.com/acts-project/acts/releases/tag/v31.0.0. No changes to the CMakeLists.txt files that need addressing in the package recipe.

The only new feature I'm a bit concerned about is acts-project/acts#2626, which replaces testing for C++20 concepts support by the feature-testing macro `__cpp_concepts`, which is also a C++20 feature. So technically we now should require `cxxstd=20` even though Acts itself still allows (and defaults to) 17. Judging by https://en.cppreference.com/w/cpp/compiler_support/20, the support for feature-testing macros was added very early by most compilers.

var/spack/repos/builtin/packages/acts/package.py

@@ -40,6 +40,9 @@ class Acts(CMakePackage, CudaPackage):
     # Supported Acts versions
     version("main", branch="main")
     version("master", branch="main", deprecated=True)  # For compatibility
+    version("31.2.0", commit="1d2e90f534ff2c9bf1c40914980b426f4b5d3096", submodules=True)
+    version("31.1.0", commit="95c3ceef79a7b68fcfc7fd558c3134d0c7529dac", submodules=True)
+    version("31.0.0", commit="2cf3fe0254d2bf9434899fdcfbe316366a970956", submodules=True)
     version("30.3.2", commit="76826f208f5929d8326798c87263f2563d0ae7e9", submodules=True)
     version("30.3.1", commit="bbee459dd93855417d5717d53cbbb2bace7de2bb", submodules=True)
     version("30.3.0", commit="311acb9ab41c2d79a4b90b193e5b25297182d670", submodules=True)