[named-fiddles] Fix named-fiddles docker image.

- Pick up git from CIPD.

Change-Id: I5685693c9c5a4010a5fefbeac43da7ee2da3dfd0
Reviewed-on: https://skia-review.googlesource.com/c/buildbot/+/307858
Auto-Submit: Joe Gregorio <jcgregorio@google.com>
Reviewed-by: Eric Boren <borenet@google.com>
Commit-Queue: Eric Boren <borenet@google.com>
diff --git a/named-fiddles/images/named-fiddles/Dockerfile b/named-fiddles/images/named-fiddles/Dockerfile
index d58390a..a7f50ec 100644
--- a/named-fiddles/images/named-fiddles/Dockerfile
+++ b/named-fiddles/images/named-fiddles/Dockerfile
@@ -1,9 +1,4 @@
-FROM gcr.io/skia-public/basealpine:3.8
-
-USER root
-
-RUN apk update && \
-    apk add --no-cache git ca-certificates tzdata
+FROM gcr.io/skia-public/base-cipd:testing-slim
 
 COPY . /