vulkan/pipeline_cache: replace raw data objects on cache insertion of real objects

vulkan/pipeline_cache: replace raw data objects on cache insertion of real objects

It might happen that a raw data object (from pipeline cache creation)
was never looked up, and thus never deserialized, before it gets
inserted again into the cache. In this case, the deserialized object
got replaced by the raw data object.
Instead, replace the raw data object with the real object in the cache.

Fixes: 8b13ee75ba9f27ceac6b6180ca05d321caa13612 ('vulkan: Fall back to raw data objects when deserializing if ops == NULL')
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/22735>