Add spelling correction for Mitigate and variants.

Author: cfi-gb

codespell_lib/data/dictionary.txt

@@ -38781,6 +38781,12 @@ misusin->misusing
 mitake->mistake
 mitaken->mistaken
 mitakes->mistakes
+mitgate->mitigate
+mitgated->mitigated
+mitgates->mitigates
+mitgating->mitigating
+mitgation->mitigation
+mitgations->mitigations
 miticate->mitigate
 miticated->mitigated
 miticateing->mitigating