Remove the test-32bit-cross job

It was not able to test as much as was desired, and there is now a
job-level container based way that does a full 32-but ARMv7 test
(facilitated by the new ARM64 runners, which are also able to
execute ARMv7 binaries without emulation).

The new ARM jobs added in the last couple of commits, consisting
of a 64-bit job in `test-fast` and a 32-bit job in `test-32bit`,
increase the total time and resources required to run CI checks.
Removing `test-32bit-cross` only slightly counteracts that. But it
is also less needed now.

.github/workflows/ci.yml

@@ -251,35 +251,6 @@ jobs:
           GIX_TEST_IGNORE_ARCHIVES: '1'
         run: cargo nextest run --workspace --no-fail-fast
 
-  test-32bit-cross:
-    runs-on: ubuntu-latest
-
-    strategy:
-      matrix:
-        target: [ armv7-linux-androideabi ]
-
-    steps:
-      - uses: actions/checkout@v4
-      - uses: dtolnay/rust-toolchain@stable
-      - uses: Swatinem/rust-cache@v2
-      - name: Install Rust
-        uses: dtolnay/rust-toolchain@master
-        with:
-          toolchain: stable
-          targets: ${{ matrix.target }}
-      - name: Install cross
-        uses: taiki-e/install-action@v2
-        with:
-          tool: cross
-      - name: check
-        run: cross check -p gix --target ${{ matrix.target }}
-      - name: Test (unit)
-        run: |
-          # Run some high-level unit tests that exercise various pure Rust code to ease building
-          # test binaries. We would prefer `-p gix`. But with `cross`, fixture scripts try to run
-          # the host `git` as an armv7 binary.
-          cross test -p gix-hashtable --target ${{ matrix.target }}
-
   lint:
     runs-on: ubuntu-latest
 
@@ -455,7 +426,6 @@ jobs:
       - test-journey
       - test-fast
       - test-32bit
-      - test-32bit-cross
       - lint
       - cargo-deny
       - check-packetline