fix some minor issues detected by CI/AI

Author: dietmarkuehl

include/beman/execution/detail/starts_on.hpp

@@ -59,7 +59,7 @@ struct starts_on_t {
         return ::beman::execution::let_value(
             ::beman::execution::schedule(scheduler),
             [new_sender = ::beman::execution::detail::forward_like<Sender>(new_sender)]() mutable noexcept(
-                ::std::is_nothrow_constructible_v<::std::decay_t<Sender>, Sender>) {
+                ::std::is_nothrow_move_constructible_v<::std::remove_cvref_t<Sender>>) {
                 return ::std::move(new_sender);
             });
     }

include/beman/execution/detail/then.hpp

@@ -119,7 +119,7 @@ struct then_t : ::beman::execution::sender_adaptor_closure<then_t<Completion>> {
     }
     template <::beman::execution::sender Sender, ::beman::execution::detail::movable_value Fun>
     auto operator()(Sender&& sender, Fun&& fun) const
-        noexcept(::std::is_nothrow_constructible_v<::std::remove_cvref_t<Sender>, Sender> && 
+        noexcept(::std::is_nothrow_constructible_v<::std::remove_cvref_t<Sender>, Sender> &&
                  ::std::is_nothrow_constructible_v<::std::remove_cvref_t<Fun>, Fun>)
     {
         auto domain{::beman::execution::detail::get_domain_early(sender)};

tests/beman/execution/exec-starts-on.test.cpp

@@ -85,7 +85,6 @@ auto test_starts_on_completions() {
     test_std::sync_wait(test::completion_test(test_std::starts_on(test_std::inline_scheduler(),
         test_std::just())));
     test_std::sync_wait(test::completion_test(test_std::just() | test_std::then([]() noexcept {})));
-    test_std::sync_wait(test::completion_test(test_std::just() | test_std::then([]() noexcept {})));
     test_std::sync_wait(test::completion_test(test_std::let_value(
         test_std::just(),
         []() noexcept { return test_std::just(); })));