when compiling with clang-tidy, it warngs:
```
[6/9] Building CXX object readers/CMakeFiles/readers.dir/multishard.cc.o
/home/kefu/dev/scylladb/readers/multishard.cc:84:53: warning: 'fut_and_result' used after it was moved [bugprone-use-after-move]
84 | auto result = std::get<1>(std::move(fut_and_result));
| ^
/home/kefu/dev/scylladb/readers/multishard.cc:79:34: note: move occurred here
79 | _read_ahead_future = std::get<0>(std::move(fut_and_result));
| ^
```
but this warning is but a false alarm, as we are not really moving away
the *whole* tuple, we are just move away an element from it. but
clang-tidy cannot tell which element we are actually moving. so, silence
both places of `std::move()`.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closesscylladb/scylladb#18363