`validation` workflow fails for `push` triggers with multi-line commit messages

Created by: c-dilks

For push triggers, the commit message is used in the dispatch payload (a json string). If a newline is used, namely in a multi-line commit message typical of PR merge commits, the dispatch will fail with the following error

parse error: Invalid string: control characters from U+0000 through U+001F must be escaped at line 4, column 7