Bump the msrv in CI

Author: akern40

.github/workflows/ci.yml

@@ -20,12 +20,16 @@ jobs:
           - stable
           - beta
           - nightly
-          - 1.64.0  # MSRV
+          - 1.65.0  # MSRV
     steps:
       - uses: actions/checkout@v4
       - uses: dtolnay/rust-toolchain@master
         with:
           toolchain: ${{ matrix.rust }}
+      - name: Pin versions for MSRV
+        if: "${{ matrix.rust == '1.65.0' }}"
+        run: |
+          cargo update -p regex --precise 1.8.4
       - name: Build
         run: cargo build --verbose
       - name: Run tests