Cleanup dependency code on macOS and add retry to git fetch

src/scripts/tools/retry.sh

@@ -0,0 +1,20 @@
+function retry {
+    local try=0
+
+    until "$@"; do
+        exit_code="$?"
+        try=$((try + 1))
+
+        if [ $try -lt 10 ]; then
+            sleep "$((2 ** try))"
+        else
+            return $exit_code
+        fi
+    done
+
+    return 0
+}
+
+function git_retry {
+    retry git "$@"
+}