build-and-provide-package: set ADDITIONAL_BUILDRESULTS also in custom pbuilderrc

If LINTIAN=yes is set, to run lintian from inside the build environment,
we need to make sure the ADDITIONAL_BUILDRESULTS reaches pbuilder.
Ad least when using a custom pbuilderrc (like
PBUILDER_CONFIG=/etc/jenkins/pbuilderrc inside /etc/jenkins/debian_glue)
then we need to make sure it's also part of the runtime pbuilderrc.

Development sponsored by Sipwise GmbH, recorded as
TT#15150 in customers' ticket system.

scripts/build-and-provide-package

@@ -304,6 +304,11 @@ cowbuilder_init() {
     echo "USENETWORK=yes" >> "$pbuilderrc"
   fi
 
+  # Will run lintian and we need pbuilder to copy the result file to $BUILDRESULT
+  if [ "${LINTIAN:-}" = 'true' ] ; then
+    echo "ADDITIONAL_BUILDRESULTS+=('../*lintian.txt')" >> "$pbuilderrc"
+  fi
+
   use_eatmydata
   use_ccache