Bumps MSRV testing on BLAS to 1.71

Closes #1464

Author: akern40

.github/workflows/ci.yaml

@@ -95,7 +95,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: dtolnay/rust-toolchain@master
         with:
-          toolchain: 1.67.0  # BLAS MSRV
+          toolchain: 1.71.0  # BLAS MSRV
       - uses: rui314/setup-mold@v1
       - uses: Swatinem/rust-cache@v2
       - name: Install openblas