Jenkins: Disable failing tests

This update should get rid of most of the temporary test failures
reported in issue [ElektraInitiative#2439](https://issues.libelektra.org/2439).

This commit closes ElektraInitiative#2439.

doc/news/_preparation_next_release.md

@@ -154,7 +154,18 @@ you up to date with the multi-language support provided by Elektra.
 
 ### Jenkins
 
-- <<TODO>>
+- We disabled the tests:
+
+  - `testmod_crypto_botan`,
+  - `testmod_crypto_openssl`,
+  - `testmod_dbus`,
+  - `testmod_dbusrecv`,
+  - `testmod_fcrypt`,
+  - `testmod_gpgme`, and
+  - `testmod_zeromqsend`
+
+  , since they are [known to fail in high load scenarios](https://issues.libelektra.org/2439). _(René Schwaiger)_
+
 - <<TODO>>
 - <<TODO>>
 

scripts/jenkins/Jenkinsfile

@@ -1200,8 +1200,23 @@ def cpuCount() {
  * @param target What target to pass to ctest
  */
 def ctest(target = "Test") {
+  /*
+     We disable the tests:
+
+     - `testmod_crypto_botan`,
+     - `testmod_crypto_openssl`,
+     - `testmod_dbus`,
+     - `testmod_dbusrecv`,
+     - `testmod_fcrypt`,
+     - `testmod_gpgme`, and
+     - `testmod_zeromqsend`
+
+     , since they are known to fail in scenarios with high load.
+     See also: https://issues.libelektra.org/2439
+  */
   sh """ctest -j ${env.CTEST_PARALLEL_LEVEL} --force-new-ctest-process \
-          --output-on-failure --no-compress-output -T ${target}"""
+          --output-on-failure --no-compress-output -T ${target}
+          -E testmod_(crypto_(botan|openssl)|dbus(recv)?|fcrypt|gpgme|zeromqsend)"""
 }
 
 /* Helper for ctest to run MemCheck without memleak tagged tests