Revert "github: add variant without git2 to CI"

The `git2` feature has been removed.

This reverts commit 8104b65e74dd55876af9655b4032fbc488985f68.

.github/workflows/ci.yml

@@ -19,16 +19,11 @@ jobs:
     strategy:
       fail-fast: ${{ github.event_name == 'merge_group' }}
       matrix:
-        build: [linux-x86_64-gnu, 'linux-x86_64-gnu, no git2', linux-aarch64-gnu, macos-x86_64, macos-aarch64, windows-x86_64]
+        build: [linux-x86_64-gnu, linux-aarch64-gnu, macos-x86_64, macos-aarch64, windows-x86_64]
         include:
         - build: linux-x86_64-gnu
           os: ubuntu-24.04
           cargo_flags: "--all-features"
-        - build: 'linux-x86_64-gnu, no git2'
-          os: ubuntu-24.04
-          cargo_flags: "--no-default-features --features git"
-          # Ensure we don’t link to `libgit2`.
-          LIBGIT2_NO_VENDOR: 1
         - build: linux-aarch64-gnu
           os: ubuntu-24.04-arm
           cargo_flags: "--all-features"
@@ -81,8 +76,6 @@ jobs:
         --all-targets
         --verbose
         ${{ matrix.cargo_flags }}
-      env:
-        LIBGIT2_NO_VENDOR: ${{ matrix.LIBGIT2_NO_VENDOR || '0' }}
     - name: Test
       run: >-
         cargo nextest run
@@ -95,7 +88,6 @@ jobs:
       env:
         RUST_BACKTRACE: 1
         CARGO_TERM_COLOR: always
-        LIBGIT2_NO_VENDOR: ${{ matrix.LIBGIT2_NO_VENDOR || '0' }}
 
   no-git:
     name: build (no git)