Update dependency mock to v5 (#2367)

Co-authored-by: elastic-renovate-prod[bot] <174716857+elastic-renovate-prod[bot]@users.noreply.github.com>
Co-authored-by: Michael Wolf <[email protected]>

Author: elastic-renovate-prod[bot]

scripts/requirements-dev.txt

@@ -1,6 +1,6 @@
 # License: MIT
 autopep8==1.6.0
 # License: BSD
-mock==4.0.3
+mock==5.1.0
 # License: GPLv3
 yamllint==1.35.1