argocd: update quay.io/argoproj/argocd Docker tag to v3.1.8

Author: renovate[bot]

argocd/kustomization.yaml

@@ -49,7 +49,7 @@ configMapGenerator:
       - gpg-keys/E6A270B1A4DA649A
 images:
   - name: quay.io/argoproj/argocd
-    newTag: v3.1.0@sha256:51abf85651c33cfd0645d72e0877eeeae187bb404d4641ec47caa1921c9750be
+    newTag: v3.1.8@sha256:19ba7f44cba487c4a0c98ac336327c4df04383dff84f87ea1a578972eb62dd17
   - name: ghcr.io/dexidp/dex
     newTag: v2.43.1@sha256:0881d3c9359b436d585b2061736ce271c100331e073be9178ef405ce5bf09557
   - name: public.ecr.aws/docker/library/redis