fix(build): pin the Rust nightly version

orhun · orhun · commit 97c30449a1b7 · 2022-03-26T21:14:22.000+03:00
Temporary fix until the `ring` build issue is fixed. - briansmith/ring#1469 - rust-lang/rust#95267
diff --git a/rust-toolchain.toml b/rust-toolchain.toml
@@ -0,0 +1,2 @@
+[toolchain]
+channel = "nightly-2022-03-22"
