Use ghc/cabal where they are installed (no toolcache)

src/setup-haskell.ts

@@ -1,29 +1,25 @@
 import * as core from '@actions/core';
-import {
-  findHaskellGHCVersion,
-  findHaskellCabalVersion,
-  cacheHaskellTool
-} from './installer';
+import {findHaskellGHCVersion, findHaskellCabalVersion} from './installer';
 
+// ghc and cabal are installed directly to /opt so use that directlly instead of
+// copying over to the toolcache dir.
+const baseInstallDir = '/opt';
 const defaultGHCVersion = '8.6.5';
-const defualtCabalVersion = '3.0';
+const defaultCabalVersion = '3.0';
 
 async function run() {
   try {
-    await cacheHaskellTool('/opt', 'ghc');
-    await cacheHaskellTool('/opt', 'cabal');
-
     let ghcVersion = core.getInput('ghc-version');
     if (!ghcVersion) {
       ghcVersion = defaultGHCVersion;
     }
-    await findHaskellGHCVersion(ghcVersion);
+    await findHaskellGHCVersion(baseInstallDir, ghcVersion);
 
     let cabalVersion = core.getInput('cabal-version');
     if (!cabalVersion) {
-      cabalVersion = defualtCabalVersion;
+      cabalVersion = defaultCabalVersion;
     }
-    await findHaskellCabalVersion(cabalVersion);
+    await findHaskellCabalVersion(baseInstallDir, cabalVersion);
   } catch (error) {
     core.setFailed(error.message);
   }