Pin proptest for MSRV

Author: tnull

.github/workflows/build.yml

@@ -43,6 +43,7 @@ jobs:
         if: matrix.msrv
         run: |
           cargo update -p hashlink --precise "0.8.2" --verbose # hashlink 0.8.3 requires hashbrown 0.14, requiring 1.64.0
+          cargo update -p proptest --precise "1.2.0" --verbose # proptest 1.3.0 requires rustc 1.64.0
       - name: Build on Rust ${{ matrix.toolchain }}
         run: cargo build --verbose --color always
       - name: Build with UniFFI support on Rust ${{ matrix.toolchain }}