Currently, flush throws no_such_column_family if a table is dropped. Skip the flush of dropped table instead.
Fixes: #16095.
Needs backport to 2025.1 and 6.2 as they contain the bug
- (cherry picked from commit 91b57e79f3)
- (cherry picked from commit c1618c7de5)
Parent PR: #23876Closesscylladb/scylladb#23905
* github.com:scylladb/scylladb:
test: test table drop during flush
replica: skip flush of dropped table