Pin quote and proc-macro2 in CI to meet MSRV

Author: TheBlueMatt

.github/workflows/build.yml

@@ -40,6 +40,11 @@ jobs:
           git checkout 0.0.115-bindings
       - name: Fix Github Actions to not be broken
         run: git config --global --add safe.directory /__w/ldk-c-bindings/ldk-c-bindings
+      - name: Pin proc-macro and quote to meet MSRV
+        run: |
+          cd c-bindings-gen
+          cargo update -p quote --precise "1.0.30" --verbose
+          cargo update -p proc-macro2 --precise "1.0.65" --verbose
       - name: Rebuild bindings without std, and check the sample app builds + links
         run: ./genbindings.sh ./rust-lightning false
       - name: Rebuild bindings, and check the sample app builds + links