slan-cuan-release: Fix slan-cuan task paths to match actual repo layout

Tasks live at tekton/tasks/slan-cuan-{task}.yaml in konflux-lightwell/slan-cuan,
not tasks/managed/slan-cuan-{task}/slan-cuan-{task}.yaml.

Assisted-by: Claude Code (Sonnet 4.6)

Author: arewm

pipelines/managed/slan-cuan-release/slan-cuan-release.yaml

@@ -334,7 +334,7 @@ spec:
           - name: revision
             value: $(params.taskGitRevision)
           - name: pathInRepo
-            value: tasks/managed/slan-cuan-extract/slan-cuan-extract.yaml
+            value: tekton/tasks/slan-cuan-extract.yaml
       runAfter:
         - collect-snapshot-params
       params:
@@ -357,7 +357,7 @@ spec:
           - name: revision
             value: $(params.taskGitRevision)
           - name: pathInRepo
-            value: tasks/managed/slan-cuan-sign/slan-cuan-sign.yaml
+            value: tekton/tasks/slan-cuan-sign.yaml
       runAfter:
         - extract
         - collect-task-params
@@ -389,7 +389,7 @@ spec:
           - name: revision
             value: $(params.taskGitRevision)
           - name: pathInRepo
-            value: tasks/managed/slan-cuan-register/slan-cuan-register.yaml
+            value: tekton/tasks/slan-cuan-register.yaml
       runAfter:
         - sign
       params:
@@ -418,7 +418,7 @@ spec:
           - name: revision
             value: $(params.taskGitRevision)
           - name: pathInRepo
-            value: tasks/managed/slan-cuan-publish/slan-cuan-publish.yaml
+            value: tekton/tasks/slan-cuan-publish.yaml
       runAfter:
         - register
         - collect-task-params