Add simple post commit reference model testing against Numpy

Only perform testing of this after build of ref model using postcommit pytest mark.

Signed-off-by: Jeremy Johnson <jeremy.johnson@arm.com>
Change-Id: I771a18d2c9cd4051fecafad3e6079b44f2ed62fa
diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index f2ccc3f..b253ddd 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -25,6 +25,6 @@
         name: pytest
         stages: [commit]
         language: system
-        entry: pytest
+        entry: pytest -m "not postcommit"
         types: [python]
         pass_filenames: false