Always fetch allRefs

Having CI confirm allRefs false is still safe would require a network
hit for each repo, which is already problematic. But
https://github.com/NixOS/nix/issues/7120 means we'd need to drop CI's
cached content, not just its cached refs: given how much we're fetching
that seems too much.

Fetch all refs unconditionally, assuming we're typically re-fetching the
same fixed rev repeatedly, which should be cached.

default.nix

@@ -52,7 +52,7 @@
 }:
 let
   inherit (lib) optionalAttrs optionalString;
-  inherit (import ./fetch-overrides.nix) extraPins extraUrls allRefsRepos;
+  inherit (import ./fetch-overrides.nix) extraPins extraUrls;
 
   # Step 1: determine which Emacs packages to pull in.
   #
@@ -239,7 +239,7 @@ let
               {
                 inherit url;
                 rev = pin;
-                allRefs = allRefsRepos.${url} or false;
+                allRefs = true;
                 submodules = !(p.recipe.nonrecursive or false);
                 # TODO: pull ref from derivation.src when not pulling it from p.recipe?
                 # Note Doom does have packages with pin + branch (or nonrecursive) set,

fetch-overrides.nix

@@ -39,10 +39,4 @@
     # In emacsattic, so shouldn't change underneath us.
     ammonite-term-repl = "b552fe21977e005c1c460bf6607557e67241a6b6";
   };
-
-  # TODO figure out whether we're better off always setting allRefs.
-  allRefsRepos = {
-    "https://git.savannah.gnu.org/git/emms.git" = true;
-    "https://git.notmuchmail.org/git/notmuch" = true;
-  };
 }