CI: fix schema publishing.

Previously, two concurrent jobs were used, which caused a race condition.
Serialize them.

.github/workflows/main.yaml

@@ -162,30 +162,6 @@ jobs:
     steps:
       - run: ${{ contains(needs.*.result, 'failure') && 'false' || 'true' }}
 
-  publish-schemas:
-    needs: document
-    if: ${{ github.repository == 'amaranth-lang/amaranth' }}
-    runs-on: ubuntu-latest
-    steps:
-      - name: Check out source code
-        uses: actions/checkout@v4
-        with:
-          fetch-depth: 0
-      - name: Download schema archive
-        uses: actions/download-artifact@v4
-        with:
-          name: schema
-          path: schema/
-      - name: Publish development schemas
-        if: ${{ github.event_name == 'push' && github.event.ref == 'refs/heads/main' }}
-        uses: JamesIves/github-pages-deploy-action@releases/v4
-        with:
-          repository-name: amaranth-lang/amaranth-lang.github.io
-          ssh-key: ${{ secrets.PAGES_DEPLOY_KEY }}
-          branch: main
-          folder: schema/
-          target-folder: schema/amaranth/
-
   publish-docs:
     needs: document
     if: ${{ github.repository == 'amaranth-lang/amaranth' }}
@@ -242,6 +218,30 @@ jobs:
           folder: pages/
           clean: false
 
+  publish-schemas:
+    needs: [required, publish-docs] # avoid race condition with publish-docs
+    if: ${{ github.repository == 'amaranth-lang/amaranth' }}
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out source code
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+      - name: Download schema archive
+        uses: actions/download-artifact@v4
+        with:
+          name: schema
+          path: schema/
+      - name: Publish schemas
+        if: ${{ github.event_name == 'push' && github.event.ref == 'refs/heads/main' }}
+        uses: JamesIves/github-pages-deploy-action@releases/v4
+        with:
+          repository-name: amaranth-lang/amaranth-lang.github.io
+          ssh-key: ${{ secrets.PAGES_DEPLOY_KEY }}
+          branch: main
+          folder: schema/
+          target-folder: schema/amaranth/
+
   publish-package:
     needs: required
     runs-on: ubuntu-latest

amaranth/lib/meta.py

@@ -135,7 +135,7 @@ def _extract_schemas(package, *, base_uri, path="schema/"):
     entry_points = distribution(package).entry_points
     for entry_point in entry_points.select(group="amaranth.lib.meta"):
         schema = entry_point.load().schema
-        relative_path = entry_point.name # v0.5/component.json
+        relative_path = entry_point.name # "0.5/component.json"
         schema_filename = pathlib.Path(path) / relative_path
         assert schema["$id"] == f"{base_uri}/{relative_path}", \
             f"Schema $id {schema['$id']} must be {base_uri}/{relative_path}"