CCtx::init using cdict and DCtx::init using ddict (experimental feature, deprecated) took the dictionary as &CDict<'b> and &DDict<'b> with only 'b: 'a, so the dictionary itself could be dropped while the context still pointed at it. The same mistake in other constructors was fixed earlier (https://github.com/gyscos/zstd-rs/issues/365).

The flaw was corrected by taking &'a CDict<'b> and &'a DDict<'b>.