Upgrade tantivy to 0.26 and clear the lru advisory

Dependabot #10: lru's IterMut violates Stacked Borrows, fixed in 0.16.3.
lru was transitive through tantivy 0.22.1, which pins lru ^0.12.0, so
there was no in-range fix -- cargo update -p lru locks nothing. The
advisory was also not reachable: tantivy calls only get, put, len,
peek_lru and new on its LruCache, never iter_mut. Upgrading rather than
dismissing because it is early enough that carrying four versions of
drift costs more than paying it now, and the alert then closes on its
own evidence rather than on an argument.

lru resolves to 0.16.4, past the patch line.

One API change across the four releases. TopDocs no longer implements
Collector on its own -- an ordering has to be chosen rather than
defaulted into. order_by_score() is exactly what bare TopDocs did in
0.22, so result order is preserved rather than quietly changed, which
matters for a search endpoint whose contract is "most relevant first".

Index compatibility checked rather than assumed, since a format change
would have meant a reindex for every existing deployment. Against a live
index of 1757 documents written by 0.22: the service opened it without
error, a document indexed hours earlier by 0.22 is still findable, new
documents written by 0.26 are findable, and a phrase query spans both.
No migration needed.

The compliance inventory is regenerated for the new graph: 17 crates
added, 5 gone, 20 bumped, and three duplicate-version entries collapsed
where the graph no longer needs two. Nothing newly flagged -- every
addition is permissive -- and cargo-deny check licenses, which is the
gate CI actually runs, passes. Rows for crates whose name and version
are unchanged are left byte-for-byte alone, so the diff shows the real
change rather than 200 rows of SPDX term reordering.

Signed-off-by: John Coffey <[email protected]>

search/Cargo.toml

@@ -14,7 +14,7 @@ tokio = { version = "1", features = ["rt-multi-thread", "macros", "fs", "sync",
 tonic = "0.12"
 prost = "0.13"
 
-tantivy = "0.22"
+tantivy = "0.26"
 rskafka = "0.6"
 
 serde = { version = "1", features = ["derive"] }