Fix various problems in the new job

- Check the specific step outcome (and specifically the outcome,
  not the conclusion which is turned into `success` by the value of
  `continue-on-error`). Without this, the last step never runs, so
  the test does not fail when it is supposed to.

- Give the last step a fixed (literal) name, since the `env` key
  does not interpolate into its name like a `matrix` value would.
  Accordingly, move the `env` key into the step, since it is now
  only used inside its logic.

- Line-buffer standard output for the `cargo nextest` command for
  more immedate (less staggered) output. This may not happen
  automatically since its stdout is a pipe. (I think its stderr is
  already either unbuffered or line-buffered even when not a
  terminal.)

Author: EliahKagan

.github/workflows/ci.yml

@@ -82,10 +82,6 @@ jobs:
 
   test-fixtures-windows:
     runs-on: windows-latest
-    env:
-      # FIXME: Change to 15 after verifying that the last step can fail.
-      # See https://github.com/GitoxideLabs/gitoxide/issues/1358.
-      EXPECTED_FAILURE_COUNT: 13
     defaults:
       run:
         shell: bash  # Includes `-o pipefail`.
@@ -97,13 +93,19 @@ jobs:
         with:
           tool: nextest
       - name: "Test (nextest)"
+        id: nextest
         env:
           GIX_TEST_IGNORE_ARCHIVES: 1
         run: |
-          cargo nextest --color=always run --workspace --no-fail-fast |& tee nextest.log
+          stdbuf -oL -- cargo nextest --color=always run --workspace --no-fail-fast |&
+            tee nextest.log
         continue-on-error: true
-      - name: Allow up to ${{ env.EXPECTED_FAILURE_COUNT }} failures
-        if: failure()
+      - name: Check how many tests failed
+        if: steps.nextest.outcome == 'failure'
+        env:
+          # FIXME: Change to 15 after verifying that the last step can fail.
+          # See https://github.com/GitoxideLabs/gitoxide/issues/1358.
+          EXPECTED_FAILURE_COUNT: 13
         run: |
           set -x
           sed -Ei 's/\x1B\[[[:digit:];]*m//g' nextest.log  # Remove ANSI color codes.