gate libloading to conduwuit_mods feature and cfg only

Signed-off-by: strawberry <strawberry@puppygock.gay>

src/core/Cargo.toml

@@ -50,6 +50,9 @@ zstd_compression = [
 ]
 perf_measurements = []
 sentry_telemetry = []
+conduwuit_mods = [
+    "dep:libloading"
+]
 
 [dependencies]
 argon2.workspace = true
@@ -75,6 +78,7 @@ ipaddress.workspace = true
 itertools.workspace = true
 libc.workspace = true
 libloading.workspace = true
+libloading.optional = true
 log.workspace = true
 num-traits.workspace = true
 rand.workspace = true