Change primgrp, smallgrp, transgrp from required to default

This way, at least in principle one can load GAP without them.

lib/package.gi

@@ -1745,9 +1745,24 @@ DeclareUserPreference( rec(
 For backwards compatibility, the default lists most of packages \
 that were autoloaded in GAP 4.4 (add or remove packages as you like)."
  ],
- default:= [ "autpgrp", "alnuth", "crisp", "ctbllib", "factint", "fga", 
- "irredsol", "laguna", "polenta", "polycyclic", "resclasses", 
- "sophus", "tomlib" ],
+ default:= [
+ "autpgrp",
+ "alnuth",
+ "crisp",
+ "ctbllib",
+ "factint",
+ "fga",
+ "irredsol",
+ "laguna",
+ "polenta",
+ "polycyclic",
+ "primgrp",
+ "resclasses",
+ "smallgrp",
+ "sophus",
+ "tomlib",
+ "transgrp",
+ ],
  values:= function() return RecNames( GAPInfo.PackagesInfo ); end,
  multi:= true,
  ) );

lib/system.g

@@ -30,9 +30,6 @@ BIND_GLOBAL( "GAPInfo", rec(
  Dependencies := MakeImmutable(rec(
  NeededOtherPackages := [
  [ "gapdoc", ">= 1.2" ],
- [ "primgrp", ">= 3.1.0" ],
- [ "smallgrp", ">= 1.0" ],
- [ "transgrp", ">= 1.0" ],
  ],
  )),
 # There is no SuggestedOtherPackages here because the default value of