Add support for short-lived tokens (#224)

The setup-gradle action tries to get a short-lived access token given the supplied Develocity access key.
This key can be passed either with the `DEVELOCITY_ACCESS_KEY` env var or via the  `develocity-access-key` input parameter.
If a token can be retrieved, then the `DEVELOCITY_ACCESS_KEY` env var will be set to the token. 
Otherwise the `DEVELOCITY_ACCESS_KEY` will be set to a blank string, to avoid a leak.

---------

Co-authored-by: daz <daz@gradle.com>

build

@@ -16,12 +16,18 @@ case "$1" in
         # Run act
         $@
         # Revert the changes to the dist directory
-        git co -- dist
+        git checkout -- dist
         ;;
     init-scripts)
         cd test/init-scripts
         ./gradlew check
         ;;
+    dist)
+        npm install
+        npm run build
+        cd ..
+        cp -r sources/dist .
+        ;;
     *)
         npm install
         npm run build