GHA: move the Testi386 job to a local workflow

.github/workflows/ci-i386.yml

@@ -0,0 +1,34 @@
+name: CI-i386
+
+'on':
+  push:
+    branches:
+      - master
+      - main
+      - '*/ci'
+  pull_request:
+    branches:
+      - master
+      - main
+  # This makes the workflow callable by curl/curl
+  workflow_call: {}
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.sha }}
+  cancel-in-progress: true
+
+permissions: {}
+
+jobs:
+  # Ensure that the repository can be built for i386
+  Testi386:
+    name: 'Test i386'
+    runs-on: ubuntu-latest
+    steps:
+      - name: Build Fuzzers
+        uses: google/oss-fuzz/infra/cifuzz/actions/build_fuzzers@master  # zizmor: ignore[unpinned-uses]
+        with:
+          oss-fuzz-project-name: 'curl'
+          dry-run: false
+          keep-unaffected-fuzz-targets: true
+          architecture: 'i386'

.github/workflows/ci.yml

@@ -91,16 +91,3 @@ jobs:
         with:
           name: artifacts
           path: ./out/artifacts
-
-  # Ensure that the repository can be built for i386
-  Testi386:
-    name: 'Test i386'
-    runs-on: ubuntu-latest
-    steps:
-      - name: Build Fuzzers
-        uses: google/oss-fuzz/infra/cifuzz/actions/build_fuzzers@master  # zizmor: ignore[unpinned-uses]
-        with:
-          oss-fuzz-project-name: 'curl'
-          dry-run: false
-          keep-unaffected-fuzz-targets: true
-          architecture: 'i386'