Update rayon to 1.6

This removes an autocfg dependency edge

src/bootstrap/Cargo.lock

@@ -468,11 +468,10 @@ dependencies = [
 
 [[package]]
 name = "rayon"
-version = "1.5.3"
+version = "1.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bd99e5772ead8baa5215278c9b15bf92087709e9c1b2d1f97cdb5a183c933a7d"
+checksum = "1e060280438193c554f654141c9ea9417886713b7acd75974c85b18a69a88e0b"
 dependencies = [
- "autocfg",
  "crossbeam-deque",
  "either",
  "rayon-core",
@@ -480,9 +479,9 @@ dependencies = [
 
 [[package]]
 name = "rayon-core"
-version = "1.9.3"
+version = "1.10.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "258bcdb5ac6dad48491bb2992db6b7cf74878b0384908af124823d118c99683f"
+checksum = "cac410af5d00ab6884528b4ab69d1e8e146e8d471201800fa1b4524126de6ad3"
 dependencies = [
  "crossbeam-channel",
  "crossbeam-deque",