Pin quote and proc-macro2 as required to get CI passing MSRV

Author: TheBlueMatt

.github/workflows/build.yml

@@ -29,6 +29,11 @@ jobs:
         uses: actions/checkout@v2
         with:
           fetch-depth: 0
+      - name: Pin syn and quote to meet MSRV
+        working-directory: lightning-c-bindings
+        run: |
+          cargo update -p syn --precise "2.0.106" --verbose
+          cargo update -p quote --precise "1.0.41" --verbose
       - name: Sanity test bindings against Cargo.toml RL
         working-directory: lightning-c-bindings
         run: |
@@ -47,6 +52,8 @@ jobs:
           git clone https://github.com/rust-bitcoin/rust-lightning
           cd rust-lightning
           git checkout 0.2-bindings
+          cargo update -p syn --precise "2.0.106" --verbose
+          cargo update -p quote --precise "1.0.41" --verbose
       - 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
@@ -89,6 +96,11 @@ jobs:
         uses: actions/checkout@v2
         with:
           fetch-depth: 0
+      - name: Pin syn and quote to meet MSRV
+        working-directory: lightning-c-bindings
+        run: |
+          cargo update -p syn --precise "2.0.106" --verbose
+          cargo update -p quote --precise "1.0.41" --verbose
       - name: Sanity test bindings against Cargo.toml RL
         working-directory: lightning-c-bindings
         run: |
@@ -107,6 +119,8 @@ jobs:
           git clone https://github.com/rust-bitcoin/rust-lightning
           cd rust-lightning
           git checkout 0.2-bindings
+          cargo update -p syn --precise "2.0.106" --verbose
+          cargo update -p quote --precise "1.0.41" --verbose
       - name: Fix Github Actions to not be broken
         run: git config --global --add safe.directory /__w/ldk-c-bindings/ldk-c-bindings
       - name: Fetch MacOS SDK