Add support for building the site via nix.

.webhook_bridge/pipeline-build-homepage-staging.yaml

@@ -44,31 +44,6 @@ spec:
                 #!/usr/bin/env sh
                 set -euo pipefail
                 echo -n "$(date +%s)" | tee $(results.unix-time.path)
-      - name: get-git-commit-time
-        taskSpec:
-          metadata: {}
-          stepTemplate:
-            image: alpine:3.20
-            computeResources:
-              requests:
-                cpu: 10m
-                memory: 600Mi
-            workingDir: "$(workspaces.repo.path)"
-          results:
-            - name: unix-time
-              description: The time of the git commit in unix timestamp format.
-          steps:
-            - image: alpine/git:v2.34.2
-              name: detect-tag-step
-              script: |
-                #!/usr/bin/env sh
-                set -euo pipefail
-                echo -n "$(git log -1 --pretty=%ct)" | tee $(results.unix-time.path)
-        workspaces:
-          - name: repo
-            workspace: git-source
-        runAfter:
-          - fetch-repository
       - name: report-pending
         taskRef:
           resolver: git
@@ -79,8 +54,6 @@ spec:
               value: f914437a46978b95f325f68d791dcf1a35738f60
             - name: pathInRepo
               value: task/gitea-set-status/0.1/gitea-set-status.yaml
-        runAfter:
-          - fetch-repository
         params:
           - name: CONTEXT
             value: "$(params.JOB_NAME)"
@@ -116,6 +89,31 @@ spec:
             value: $(params.PULL_BASE_SHA)
           - name: deleteExisting
             value: "true"
+      - name: get-git-commit-time
+        taskSpec:
+          metadata: {}
+          stepTemplate:
+            image: alpine:3.20
+            computeResources:
+              requests:
+                cpu: 10m
+                memory: 600Mi
+            workingDir: "$(workspaces.repo.path)"
+          results:
+            - name: unix-time
+              description: The time of the git commit in unix timestamp format.
+          steps:
+            - image: alpine/git:v2.34.2
+              name: detect-tag-step
+              script: |
+                #!/usr/bin/env sh
+                set -euo pipefail
+                echo -n "$(git log -1 --pretty=%ct)" | tee $(results.unix-time.path)
+        workspaces:
+          - name: repo
+            workspace: git-source
+        runAfter:
+          - fetch-repository
       - name: build-image
         taskRef:
           resolver: git