Update dependencies (#368)

.github/workflows/ci.yml

@@ -24,6 +24,14 @@ jobs:
       fail-fast: false
     steps:
       - uses: actions/checkout@v4
+      - name: Downgrade packages for MSRV
+        if: matrix.rust == '1.70.0'
+        run: |
+          cargo add --dev jsonschema@0.20
+          cargo add --dev garde --git https://github.com/jprochazk/garde.git --rev be00ddddf8de14530ee890ccfdbaf0b13fb32852
+          cargo add --dev validator@0.18.1
+          cargo update url --precise 2.5.2
+        working-directory: ./schemars
       - uses: dtolnay/rust-toolchain@master
         with:
           toolchain: ${{ matrix.rust }}