Said method passes down its `diff` input to `mutate_internal()`, after
some std::ranges massaging. Said massaging is destructive -- it moves
items from the diff. If the output range is iterated-over multiple
times, only the first time will see the actual output, further
iterations will get an empty range.
When trace-level logging is enabled, this is exactly what happens:
`mutate_internal()` iterates over the range multiple times, first to log
its content, then to pass it down the stack. This ends up resulting in
a range with moved-from elements being pased down and consequently write
handlers being created with nullopt mutations.
Make the range re-entrant by materializing it into a vector before
passing it to `mutate_internal()`.
Fixes: scylladb/scylladb#21907Fixes: scylladb/scylladb#21714Closesscylladb/scylladb#21910
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