Improve completion support

ghcup.cabal

@@ -241,14 +241,18 @@ executable ghcup
     , optparse-applicative  >=0.15.1.0 && <0.17
     , pretty                ^>=1.1.3.1
     , pretty-terminal       ^>=0.1.0.0
+    , process               ^>=1.6.11.0
     , resourcet             ^>=1.2.2
     , safe                  ^>=0.3.18
     , safe-exceptions       ^>=0.1
+    , tagsoup               ^>=0.14
     , temporary             ^>=1.3
     , template-haskell      >=2.7      && <2.18
     , text                  ^>=1.2.4.0
+    , unordered-containers  ^>=0.2
     , uri-bytestring        ^>=0.3.2.2
     , utf8-string           ^>=1.0
+    , vector                ^>=0.12
     , versions              >=4.0.1    && <5.1
     , yaml-streamly         ^>=0.12.0
 
@@ -262,7 +266,6 @@ executable ghcup
       , brick         ^>=0.64
       , transformers  ^>=0.5
       , unix          ^>=2.7
-      , vector        ^>=0.12
       , vty           >=5.28.2 && <5.34
 
   if os(windows)