Rename v7 of nom to nom-old

Summary: Nom v7 to v8 turns out to be too invasive to upgrade in one diff for the whole repo. This diff renames the existing import of nom v7 to "nom-old", and D75796557 will import nom v8 as "nom". After upgrading the usages one-by-one from nom-old to nom, v7 can be removed.

Differential Revision: D75796558

fbshipit-source-id: fde992d01687834e8c190b0ac929898433d3a7f9

Author: David Tolnay

eden/mononoke/hgproto/BUCK

@@ -22,7 +22,7 @@ rust_library(
         "fbsource//third-party/rust:futures",
         "fbsource//third-party/rust:hex",
         "fbsource//third-party/rust:itertools",
-        "fbsource//third-party/rust:nom",
+        "fbsource//third-party/rust:nom-old",
         "fbsource//third-party/rust:pin-project",
         "fbsource//third-party/rust:thiserror",
         "fbsource//third-party/rust:tokio",

eden/mononoke/mercurial/BUCK

@@ -33,7 +33,7 @@ rust_library(
         "fbsource//third-party/rust:bytes",
         "fbsource//third-party/rust:flate2",
         "fbsource//third-party/rust:memmap2",
-        "fbsource//third-party/rust:nom",
+        "fbsource//third-party/rust:nom-old",
         "fbsource//third-party/rust:thiserror",
         ":mercurial_types",
         "//eden/scm/lib/lz4-pyframe:lz4-pyframe",