Set +x in index in other gix-status fixtures

For these the current situation is simpler because the tests
currently using them do not contain assertions whose correctness
varies based on whether the affected files modes' have +x or -x.

But it is the intent of the fixtures to record +x modes for some
particular files in the test repository, so this modifies the
scripts to do so, even on Windows where `chmod +x` does not take
effect.

This also allows the tests to include a broader range of metadata
and, specifically, may verify in some comparisons that having a
mode of 0o755 instead of 0o644 does not cause a problem, even
though not explicitly asserted in detail.

gix-status/tests/fixtures/status_many.sh

@@ -12,6 +12,7 @@ git init -q changed-and-untracked
   echo "different content" > dir/content2
 
   git add -A
+  git update-index --chmod=+x executable  # For Windows.
   git commit -m "Commit"
   echo "change" >> executable
 

gix-status/tests/fixtures/status_removed.sh

@@ -13,6 +13,7 @@ mkdir dir/sub-dir
 (cd dir/sub-dir && ln -sf ../content symlink)
 
 git add -A
+git update-index --chmod=+x executable  # For Windows.
 git commit -m "Commit"
 rm -rf ./empty ./executable ./dir/content ./dir/sub-dir/symlink
-git reset 
+git reset

gix-status/tests/fixtures/status_unchanged.sh

@@ -13,8 +13,9 @@ mkdir dir/sub-dir
 (cd dir/sub-dir && ln -sf ../content symlink)
 
 git add -A
+git update-index --chmod=+x executable  # For Windows.
 git commit -m "Commit"
 
 touch ./empty ./executable ./dir/content ./dir/sub-dir/symlink
 
-git reset # ensure index timestamp is large enough to not mark everything racy
+git reset # ensure index timestamp is large enough to not mark everything racy