Everywhere: Use ReadonlySpan<T> instead of Span<T const>

Author: https://github.com/MacDue
Commit: 63b11030f0
Pull-request: https://github.com/SerenityOS/serenity/pull/17328
Reviewed-by: https://github.com/trflynn89

Kernel/Interrupts/GenericInterruptHandler.cpp

@@ -67,7 +67,7 @@ void GenericInterruptHandler::change_interrupt_number(u8 number)
     register_generic_interrupt_handler(InterruptManagement::acquire_mapped_interrupt_number(interrupt_number()), *this);
 }
 
-Span<u32 const> GenericInterruptHandler::per_cpu_call_counts() const
+ReadonlySpan<u32> GenericInterruptHandler::per_cpu_call_counts() const
 {
     return m_per_cpu_call_counts.span().slice(0, Processor::count());
 }