ci: Test on both main and dev validator branches

.github/workflows/validate_datasets.yml

@@ -21,7 +21,7 @@ jobs:
       fail-fast: false
       matrix:
         platform: [ubuntu-latest, macos-latest, windows-latest]
-        bids-validator: [stable, dev, legacy]
+        bids-validator: [stable, main, dev, legacy]
 
     runs-on: ${{ matrix.platform }}
 
@@ -49,14 +49,22 @@ jobs:
           deno install -Agf -n bids-validator jsr:@bids/validator
       shell: bash
 
-    - name: Install BIDS validator (dev)
-      if: matrix.bids-validator == 'dev'
+    - name: Install BIDS validator (main)
+      if: matrix.bids-validator == 'main'
       run: |
         # If unmerged validator PRs are needed for testing, you can use
         # https://github.com/<FORK>/bids-validator/raw/<BRANCH>/bids-validator/src/bids-validator.ts
         deno install -Agf https://github.com/bids-standard/bids-validator/raw/deno-build/bids-validator.js
       shell: bash
 
+    - name: Install BIDS validator (dev)
+      if: matrix.bids-validator == 'dev'
+      run: |
+        git clone -b dev https://github.com/bids-standard/bids-validator/ ../bids-validator
+        cd ../bids-validator
+        deno install -Agf src/bids-validator.ts
+      shell: bash
+
     - name: Install BIDS validator (legacy)
       if: "matrix.bids-validator == 'legacy'"
       run: |