Make macOS R installation sequential

Hopefully this solves installer hangs.

Author: gaborcsardi

setup-r/lib/installer.js

@@ -102,11 +102,9 @@ function acquireR(version, rtoolsVersion) {
                 ]);
             }
             else if (IS_MAC) {
-                yield Promise.all([
-                    acquireFortranMacOS(),
-                    acquireUtilsMacOS(),
-                    acquireRMacOS(version)
-                ]);
+                yield acquireFortranMacOS();
+                yield acquireUtilsMacOS();
+                yield acquireRMacOS(version);
                 if (core.getInput("remove-openmp-macos") === "true") {
                     yield removeOpenmpFlags();
                 }

setup-r/src/installer.ts

@@ -70,11 +70,9 @@ async function acquireR(version: string, rtoolsVersion: string) {
         acquireQpdfWindows()
       ]);
     } else if (IS_MAC) {
-      await Promise.all([
-        acquireFortranMacOS(),
-        acquireUtilsMacOS(),
-        acquireRMacOS(version)
-      ]);
+      await acquireFortranMacOS();
+      await acquireUtilsMacOS();
+      await acquireRMacOS(version);
       if (core.getInput("remove-openmp-macos") === "true") {
         await removeOpenmpFlags();
       }