update proc-macro2

Author: RalfJung

src/tools/miri/test-cargo-miri/Cargo.lock

@@ -102,9 +102,9 @@ checksum = "3fdb12b2476b595f9358c5161aa467c2438859caa136dec86c26fdd2efe17b92"
 
 [[package]]
 name = "proc-macro2"
-version = "1.0.66"
+version = "1.0.79"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "18fb31db3f9bddb2ea821cde30a9f70117e3f119938b5ee630b7403aa6e2ead9"
+checksum = "e835ff2298f5721608eb1a980ecaee1aef2c132bf95ecc026a11b7bf3c01c02e"
 dependencies = [
  "unicode-ident",
 ]