Exclude pre-1.60 crates from workspace

Pre-1.60 crates can't be used in workspaces with other crates that use
namespaced/weak features.

This commit places all MSRV 1.60+ crates into `members` and moves the
ones with earlier MSRVs into `exclude`.

Cargo.toml

@@ -1,21 +1,21 @@
 [workspace]
 resolver = "2"
 members = [
-    "aead",
     "cipher",
+    "crypto",
     "crypto-common",
     "digest",
+    "elliptic-curve",
     "kem",
     "password-hash",
+]
+# TODO: re-add to `members` when MSRV has been bumped to 1.60+
+exclude = [
+    "aead",
     "signature",
     "signature/async",
     "universal-hash",
 ]
-# re-add when all crates are MSRV 1.60+
-exclude = [
-    "crypto",
-    "elliptic-curve"
-]
 
 [patch.crates-io]
 block-buffer = { git = "https://github.com/RustCrypto/utils.git" }