Some minor things that aren't worth individual PRs or CIs. These are almost entirely non-functional changes.

• Pretty clang-format find/version check messages: Let's make these more consistent with the messages for find_package(Python) and the assembler. Showing the path may help folks with problems.
• Remove extraneous element_type from ContiguousIterator: While we're here, let's use value_type and difference_type where appropriate so we can see which int is which.
• Remove unused include from P2163R3_invoke_r: This test doesn't need is_permissive.hpp after Adjust tests relying on CWG-1351 noexcept behavior #4914.
• Investigate a couple of libc++ failures.
• Add some missing #endif comments: These were incorrectly removed by Begin removing EDG workaround from ranges::to tests #4944.
• Change "ASAN" to the canonical "ASan" in expected_results.txt comments.
• Remove an imprecise comment on the primary template of formatter suggesting that a deleted default constructor is sufficient for a disabled specialization.
• Cleanup unintended test configuration names. The internal "Runall" test runner interprets trailing comments on configuration lines as providing a name to refer to that configuration in run reports. The STL conventionally avoids such names, forcing Runall to tell us the actual command line instead.