x/build/internal/task/releaselet: Windows installer Dialog{,Left}.jpg images contain old Go website URL

[rillig]

What version of Go are you using (go version)?

go1.19.4

What did you do?

• install https://go.dev/dl/go1.19.4.windows-amd64.msi

What did you expect to see?

• The image in the installer has a URL starting with https instead of http.
• The image in the installer links to go.dev instead of golang.org.

What did you see instead?

[dr2chase]

CC @golang/release