Jenkinsfile: reduce CI resource using while debugging

While we are debugging, limit the number of environment on which we're
running so that we don't waste a bunch of resources.  Make all the
lists empty so that the only check we do is the "distcheck" entry,
below.

Signed-off-by: Jeff Squyres <[email protected]>

Author: jsquyres

.ci/community-jenkins/Jenkinsfile

@@ -3,6 +3,7 @@
 // Copyright (c) 2022-2023 Amazon.com, Inc. or its affiliates.  All rights
 //                         reserved.
 // Copyright (c) 2022-2023 Joe Downs.  All rights reserved.
+// Copyright (c) 2023      Cisco Systems, Inc.  All rights reserved.
 // $COPYRIGHT$
 //
 // Additional copyrights may follow
@@ -47,6 +48,17 @@ def prepare_check_stages() {
     def configure_options = ["--disable-dlopen", "--disable-oshmem", "--enable-builtin-atomic", "--enable-ipv6"]
     def compilers = ["clang10", "gcc5", "gcc6", "gcc7", "gcc8", "gcc9", "gcc10"]
     def platforms = ["amazon_linux_2", "amazon_linux_2-arm64", "rhel7", "rhel8", "ubuntu_18.04"]
+
+    // TODO: While we are debugging, limit the number of combinations
+    // that we're running so that we don't waste a bunch of resources.
+    // Make all the lists empty so that the only check we do is the
+    // "distcheck" entry, below.  When we have finished debugging,
+    // remove the following lines so that we go back to the full set
+    // of test environments.
+    configure_options = []
+    compilers = []
+    platforms = []
+
     def check_stages_list = []
 
     // Build everything stage