Remove unused test infrastructure (#11529)

These two files haven't been touched since 2016 and don't appear to be
referenced anywhere else

tests/run-tests.sh

@@ -1,8 +0,0 @@
-#! /bin/bash
-
-# curl -# -C - -o shebang-unit https://raw.github.com/arpinum-oss/shebang-unit/master/releases/shebang-unit
-# chmod +x shebang-unit
-
-now=$(date +"%Y%m%d%H%M%S")
-mkdir -p ${PWD}/tests-results
-./shebang-unit --reporters=simple,junit --output-file=${PWD}/tests-results/junit_report-${now}.xml tests