MDBF-887 - LDD Minor upgrade tests fail on RHEL ha_spider.so

As investigated in https://jira.mariadb.org/browse/MDBF-887
by me and Elena, it seems that running LDD on
ha_spider.so-10.6.20-1.el8.x86_64.debug yields either return code 0 or 1 on different server versions
with no really useful output for the comparison. Although the file is in ELF format
and dynamically linked, LDD cannot provide any useful output.

ldd ha_spider.so-10.6.20-1.el8.x86_64.debug
ldd: warning: you do not have execution permission for `./ha_spider.so-10.6.20-1.el8.x86_64.debug'

$ echo $?
1

ldd ha_spider.so-10.6.21-1.el8.x86_64.debug
ldd: warning: you do not have execution permission for `./ha_spider.so-10.6.21-1.el8.x86_64.debug'
	statically linked

$ echo $?
0

This underlying issue may be the subject to another task, for now
in order to exclude the false-positive results from Buildbot
and save developers time on looking on these, it's best to exclude the -debuginfo packages
from collect_dependencies().

How to test this PR:
-> use a fresh RHEL 8 virtual machine
-> clone buildbot repo and checkout this PR
-> run ./scripts/rpm-upgrade.sh https://buildbot.mariadb.org/#/builders/743/builds/178
   ( the above step will reproduce what buildbot does)

one can use any link to a failed build for the current arch/os variant in the rpm-upgrade command.

scripts/bash_lib.sh

@@ -679,6 +679,11 @@ collect_dependencies() {
   # Spider_package_list variable does not exist for RPM upgrades.
   set +u
   for p in ${package_list} ${spider_package_list} ; do
+    # TEMP: Skip debuginfo packages as ldd is not reliable. See MDBF-887
+    if [[ "$p" =~ -debuginfo$ ]]; then
+      continue
+    fi
+
     if [[ "$p" =~ columnstore ]] ; then
       suffix="columnstore"
     else