pre-commit: apply autofixes hooks and fix the rest manually

- markdownlint (manual fix)
- end-of-file-fixer
- requirements-txt-fixer
- trailing-whitespace

contrib/terraform/upcloud/modules/kubernetes-cluster/variables.tf

@@ -106,4 +106,4 @@ variable "server_groups" {
     anti_affinity_policy = string
     servers              = list(string)
   }))
-}
+}