chore: Use Cargo metadata for the MSRV build job

Author: nickelc

.github/workflows/ci.yml

@@ -18,9 +18,6 @@ jobs:
           - stable
           - beta
           - nightly
-          # When updating this value, don't forget to also adjust the
-          # `rust-version` field in the `Cargo.toml` file.
-          - 1.49.0
 
         include:
           - rust: nightly
@@ -51,10 +48,16 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v3
 
-      - name: Install Rust
+      - name: Get MSRV from package metadata
+        id: metadata
+        run: |
+          cargo metadata --no-deps --format-version 1 |
+              jq -r '"msrv=" + (.packages[] | select(.name == "http")).rust_version' >> $GITHUB_OUTPUT
+
+      - name: Install Rust (${{ steps.metadata.outputs.msrv }})
         uses: dtolnay/rust-toolchain@master
         with:
-          toolchain: "1.49"
+          toolchain: ${{ steps.metadata.outputs.msrv }}
 
       - name: Test
         run: cargo test -p http