ci: Drop minimal test run

Author: chriswk

.github/workflows/test.yaml

@@ -33,23 +33,6 @@ jobs:
       # https://github.com/rust-lang/cargo/issues/6669
       - name: cargo test --doc
         run: cargo test --locked --all-features --doc
-  minimal:
-    runs-on: ubuntu-latest
-    name: ubuntu / stable / minimal-versions
-    steps:
-      - uses: actions/checkout@v3
-        with:
-          submodules: true
-      - name: Install stable
-        uses: dtolnay/rust-toolchain@stable
-      - name: Install nightly for -Zminimal-versions
-        uses: dtolnay/rust-toolchain@nightly
-      - name: rustup default stable
-        run: rustup default stable
-      - name: cargo update -Zminimal-versions
-        run: cargo +nightly update -Zminimal-versions
-      - name: cargo test
-        run: cargo test --locked --all-features --all-targets
   os-check:
     runs-on: ${{ matrix.os }}
     name: ${{ matrix.os }} / stable