fix(kargo): fix soak time format and add tagSuffix to staging stages

Change requiredSoakTime from 5m to 5m0s (Kargo duration format).
Add explicit tagSuffix="" to staging and eu-central-1-prod stages to
satisfy Kargo 1.10.x admission webhook variable resolution.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

kargo-projects/nowchess/ncs-stage.yaml

@@ -11,6 +11,8 @@ spec:
       value: nowchess-staging
     - name: folder
       value: eu-central-1-staging
+    - name: tagSuffix
+      value: ""
   requestedFreight:
     - origin:
         kind: Warehouse
@@ -91,6 +93,8 @@ spec:
       value: nowchess
     - name: folder
       value: eu-central-1-prod
+    - name: tagSuffix
+      value: ""
   requestedFreight:
     - origin:
         kind: Warehouse