Bug 41247: Drop sha512 hash from update_responses files (except for nightly)

With tor-browser#42737, the sha512 hash included in the update_responses
files is not checked anymore. Since we're doing a watershed update,
support for older versions checking the hash is not needed.

However since we don't do watershed updates in nightly, we'll keep the
sha512 hash in nightly for a little more time.

tools/signing/nightly/config.yml

 ---
+hashes_in_responses: 1
 martools_version: 9.0.2
 martools_url: https://archive.torproject.org/tor-package-archive/torbrowser/
 martools_gpg_keyring: keyring/torbrowser.gpg

tools/update-responses/update_responses

@@ -107,8 +107,10 @@ sub get_version_files {
                 type => 'complete',
                 URL => "$download_url/$file",
                 size => -s "$vdir/$file",
+                $config->{hashes_in_responses} ? (
                     hashFunction => 'SHA512',
                     hashValue => get_sha512_hex_of_file("$vdir/$file"),
+                ) : (),
             };
             next;
         }
@@ -118,9 +120,11 @@ sub get_version_files {
                 type => 'partial',
                 URL => "$download_url/$file",
                 size => -s "$vdir/$file",
+                $config->{hashes_in_responses} ? (
                     hashFunction => 'SHA512',
                     hashValue => get_sha512_hex_of_file("$vdir/$file"),
-            }
+                ) : (),
+            };
         }
     }
     closedir $d;
@@ -241,8 +245,10 @@ sub create_incremental_mar {
             type => 'partial',
             URL => "$download_url/$mar_file",
             size => -s $mar_file_path,
+            $config->{hashes_in_responses} ? (
                 hashFunction => 'SHA512',
                 hashValue => get_sha512_hex_of_file($mar_file_path),
+            ) : (),
         };
     };
     return if $pm->start($finished_file);