Downgraded clap version to be compatible with MSRV

Andrew J Westlake · Andrew J Westlake · commit cd90437185f7 · 2022-10-06T23:03:41.000Z
diff --git a/Cargo.toml b/Cargo.toml
@@ -111,7 +111,7 @@ required-features = ["async-std-runtime", "testing"]
 
 [dependencies]
 async-channel = { version = "1.6", optional = true }
-clap = { version = "4.0.10", optional = true }
+clap = { version = "3.2", optional = true }
 futures = "0.3"
 inventory = { version = "0.3", optional = true }
 once_cell = "1.14"
