Remove superfluous catch_reporter_registrars.hpp includes from reporters

The includes were an artifact of the old design where the built-in
reporter TUs used autoregistration to add the reporters to the
factory. Because the current design is to add them explicitly in
the central reporter factory TU, the includes are useless.

src/catch2/reporters/catch_reporter_console.cpp

@@ -10,7 +10,6 @@
 
 #include <catch2/interfaces/catch_interfaces_config.hpp>
 #include <catch2/catch_test_spec.hpp>
-#include <catch2/catch_reporter_registrars.hpp>
 #include <catch2/internal/catch_console_colour.hpp>
 #include <catch2/internal/catch_string_manip.hpp>
 #include <catch2/catch_version.hpp>

src/catch2/reporters/catch_reporter_junit.cpp

@@ -12,7 +12,6 @@
 
 #include <catch2/catch_tostring.hpp>
 #include <catch2/internal/catch_string_manip.hpp>
-#include <catch2/catch_reporter_registrars.hpp>
 #include <catch2/internal/catch_textflow.hpp>
 #include <catch2/interfaces/catch_interfaces_config.hpp>
 #include <catch2/catch_test_case_info.hpp>