Tests fail on windows with 'FINDSTR: /= ignored'

Around 45 tests in this repo are failing on windows with what looks like the same underlying issue:

```
INFO: From Testing //bazel_integration_test/private:bzlformat_no_deps_utils_bzl_fmttest:
==================== Test output for //bazel_integration_test/private:bzlformat_no_deps_utils_bzl_fmttest:
FINDSTR: /= ignored
FINDSTR: /" ignored
FINDSTR: /= ignored
FINDSTR: /" ignored
FAIL: files "bazel_integration_test/private/no_deps_utils.bzl" and "bazel_integration_test/private/no_deps_utils.bzl.formatted" differ.
================================================================================
```

To reproduce, windows 10:
```
git clone
cd rules_bazel_integration_test
bazel test //bazel_integration_test/private:bzlformat_no_deps_utils_bzl_fmttest
bazel clean
bazel --windows_enable_symlinks test //bazel_integration_test/private:bzlformat_no_deps_utils_bzl_fmttest
bazel clean
bazel --windows_enable_symlinks test //bazel_integration_test/private:bzlformat_no_deps_utils_bzl_fmttest --enable_runfiles
```

At a minimum I believe the last invocation should be supported.

I can contribute a fix to this, if it would help.