The DuckDB schema init loaded the vss and fts extensions but nothing ever
installed them, so any machine without them already present failed with
'IO Error: Extension "vss.duckdb_extension" not found'. This surfaced as 13
failing tests in CI while passing locally, because local runs had the
extensions installed already.
Loading is attempted first so an extension that is already present costs
nothing and never touches the network; INSTALL is reached only once, on a
machine seeing the extension for the first time, and reports an actionable
message if it cannot download.
CI cached the extension directory but nothing populated it, so the cache
saved an empty directory forever. The cache key now derives from Cargo.lock
rather than a hardcoded DuckDB version, and a step on cache miss installs the
extensions so the post-job save has something to store.
Dark-Alex-17
f68937611e