Try enabling musl tests on CI

.github/workflows/test.yml

@@ -21,12 +21,7 @@ jobs:
           # mac-14 is an M1 ARM device.
           - { target: aarch64-apple-darwin, os: macos-14 }
 
-          # musl binaries produced by GitHub actions segfault when run, see
-          # https://github.com/Wilfred/difftastic/issues/563
-          #
-          # musl builds seem to work fine elsewhere, so just verify
-          # that compilation works for now.
-          - { target: x86_64-unknown-linux-musl, os: ubuntu-20.04, use-cross: true, build-only: true }
+          - { target: x86_64-unknown-linux-musl, os: ubuntu-20.04, use-cross: true }
     env:
       BUILD_CMD: cargo
       SUBCOMMAND: test
@@ -51,11 +46,6 @@ jobs:
       shell: bash
       run: echo "BUILD_CMD=cross" >> $GITHUB_ENV
 
-    - name: Overwrite build subcommand env variable
-      if: matrix.job.build-only
-      shell: bash
-      run: echo "SUBCOMMAND=build" >> $GITHUB_ENV
-
     - name: Test
       shell: bash
       run: $BUILD_CMD $SUBCOMMAND --target ${{ matrix.job.target }}