Allow linking against system-provided libsqlite

Unfortunately, rusqlite uses the opposite logic for enabling/disabling
bundled libraries to others (libsodium-sys, zstd-sys). Cargo features
are very limited and doesn't allow to enable feature A in a dependency
iff feature B is disabled.

Note, lmdb-rkv-sys doesn't need any special treatment because it
automatically links against system liblmdb if found via pkgconf.

Linux distros should build garage with
`--no-default-features --features system-libs` to disable bundled-libs
and enable system-libs.

src/db/Cargo.toml

@@ -22,7 +22,7 @@ hexdump = "0.1"
 tracing = "0.1.30"
 
 heed = "0.11"
-rusqlite = { version = "0.27", features = ["bundled"] }
+rusqlite = "0.27"
 sled = "0.34"
 
 # cli deps
@@ -33,4 +33,5 @@ pretty_env_logger = { version = "0.4", optional = true }
 mktemp = "0.4"
 
 [features]
+bundled-libs = [ "rusqlite/bundled" ]
 cli = ["clap", "pretty_env_logger"]