QL: Bump rust to 1.68

hmac · hmac · commit f2fc80b3c141 · 2023-03-23T11:59:14.000+13:00
diff --git a/ql/rust-toolchain.toml b/ql/rust-toolchain.toml
@@ -2,6 +2,6 @@
 # extractor. It is set to the lowest version of Rust we want to support.
 
 [toolchain]
-channel = "1.59"
+channel = "1.68"
 profile = "minimal"
 components = [ "rustfmt" ]
