Ensure sequential execution of test scripts

Added a wait command to ensure sequential execution of tests.

Author: plengauer

tests/run_tests.sh

@@ -38,6 +38,7 @@ for dir in unit sdk auto integration performance; do
     chmod 0666 "$stdout" "$stderr"
     export OTEL_SHELL_SDK_STDERR_REDIRECT="$stderr"
     ( timeout $((60 * 60 * 3)) $TEST_SHELL $options "$file" 1> "$stdout" 2> "$stderr" && echo "$file SUCCEEDED" || (echo "$file FAILED" && echo "stdout:" && cat "$stdout" && echo "stderr:" && cat "$stderr" && echo "otlp:" && cat "$OTEL_EXPORT_LOCATION" && touch "$failed_flag" && exit 1) ) 2>&1 | perl -e '$| = 1; print while <>;' &
+    wait # TODO force sequential for now
     [ "$dir" != performance ] || wait
   done < <({ find $dir -iname 'test_*.sh'; find $dir -iname 'test_*.'"$SHELL"; } | sort -u)
   wait