Cargo: Enable unreachable pub lint

In order to prevent the problem that previous commit fixed, enable this
lint for all of our crates.

fixup

Author: Lorak-mmk

scylla-cql/Cargo.toml

@@ -44,3 +44,6 @@ num-bigint-03 = ["dep:num-bigint-03"]
 num-bigint-04 = ["dep:num-bigint-04"]
 bigdecimal-04 = ["dep:bigdecimal-04"]
 full-serialization = ["chrono", "time", "secret", "num-bigint-03", "num-bigint-04", "bigdecimal-04"]
+
+[lints.rust]
+unreachable_pub = "warn"

scylla-macros/Cargo.toml

@@ -15,4 +15,7 @@ proc-macro = true
 darling = "0.20.0"
 syn = "2.0"
 quote = "1.0" 
-proc-macro2 = "1.0"
+proc-macro2 = "1.0"
+
+[lints.rust]
+unreachable_pub = "warn"

scylla-proxy/Cargo.toml

@@ -32,3 +32,5 @@ ntest = "0.9.0"
 tracing-subscriber = { version = "0.3.14", features = ["env-filter"] }
 tokio = { version = "1.12", features = ["signal"] }
 
+[lints.rust]
+unreachable_pub = "warn"

scylla/Cargo.toml

@@ -70,3 +70,6 @@ time = "0.3"
 [[bench]]
 name = "benchmark"
 harness = false
+
+[lints.rust]
+unreachable_pub = "warn"