notify users to update their build scripts if using rocksdb or sha256_media

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

src/core/Cargo.toml

@@ -45,6 +45,10 @@ zstd_compression =[]
 perf_measurements = []
 sentry_telemetry = []
 
+# these do nothing, these are purely for informing users to update their build scripts if they use one
+rocksdb = []
+sha256_media = []
+
 [dependencies]
 argon2.workspace = true
 axum.workspace = true