adding false positive for the common.key file in kci

this file intedned for the ephemeral local cluster setup
therefore it doesn't impose any security breach by exposing it
in the repo.

Signed-off-by: Igor Bezukh <ibezukh@redhat.com>

Author: enp0s3

.gitleaks.toml

@@ -0,0 +1,7 @@
+kubevirtci/cluster-up/hack/common.key
+[allowlist]
+  description = "kubevirtci allowlist"
+  paths = [
+    # Ignore some long path
+    '''kubevirtci\/cluster-up\/hack\/common.key$''',
+  ]