removed --no-lock from source distribution build script

Author: Aiden2244

setup/mac/source_distribution/install_prereqs.sh

@@ -32,4 +32,8 @@ if ! command -v brew &>/dev/null; then
   exit 4
 fi
 
-brew bundle --file="${BASH_SOURCE%/*}/Brewfile" --no-lock
+# Do not genereate a brew lockfile. This behavior was previously implemented
+# with the now deprecated '--no-lock' flag. This env variable allows
+# for the behavior to be consistent without using the flag.
+export HOMEBREW_BUNDLE_NO_LOCK=1
+brew bundle --file="${BASH_SOURCE%/*}/Brewfile"