Disable Marginalia line backtrace in production

Merged Stan Hu requested to merge sh-disable-line-in-marginalia into master

As mentioned in https://github.com/basecamp/marginalia/pull/93/files, adding :line to the output of the Marginalia incurs some overhead because a regexp on the backtrace has to be run on every SQL query. Only enable this in development because we've seen it slow things down.

Identified in #198694 (closed)

Edited by Stan Hu