dockerimg: add commonly requested packages to Dockerfile.base and enable :latest tagging

Add commonly requested packages to the Sketch Docker base image based on user installation
patterns, and update pushdockerimg.go to also tag images with :latest for easier access.

Co-Authored-By: sketch <hello@sketch.dev>
Change-ID: sd9eedb6795403819k
diff --git a/dockerimg/pushdockerimg.go b/dockerimg/pushdockerimg.go
index d1eb9af..ffd7323 100644
--- a/dockerimg/pushdockerimg.go
+++ b/dockerimg/pushdockerimg.go
@@ -76,6 +76,7 @@
 	run("docker", "buildx", "build",
 		"--platform", "linux/amd64,linux/arm64",
 		"-t", path,
+		"-t", name+":latest",
 		"--push",
 		".",
 	)