Inline the cargo cache autoclean step.

.lighthouse/pipeline-rust-test.yaml

@@ -168,18 +168,39 @@ spec:
           - name: TARGET_URL
             value: "https://tekton.fizz.buzz/#/namespaces/$(context.pipelineRun.namespace)/pipelineruns/$(context.pipelineRun.name)"
       - name: cargo-cache-autoclean
-        taskRef:
+        taskSpec:
-          name: run-docker-image
+          metadata: {}
+          params:
+            - name: docker-image
+              type: string
+              description: Docker image to run.
+              default: alpine:3.18
+          stepTemplate:
+            image: alpine:3.18
+            name: ""
+            resources:
+              requests:
+                cpu: 10m
+                memory: 600Mi
+            workingDir: /workspace/source
+          workspaces:
+            - name: source
+              mountPath: /source
+            - name: cargo-cache
+              mountPath: /usr/local/cargo/registry
+              optional: true
+          steps:
+            - name: run
+              image: $(params.docker-image)
+              workingDir: "$(workspaces.source.path)"
+              command: [cargo, cache, --autoclean]
+              args: []
         workspaces:
           - name: source
             workspace: git-source
           - name: cargo-cache
             workspace: cargo-cache
         params:
-          - name: command
-            value: [cargo, cache, --autoclean]
-          - name: args
-            value: []
           - name: docker-image
             value: "$(params.image-name):$(tasks.fetch-repository.results.commit)"
     workspaces: