Fix warnings on Windows. (backport #2692)

[mergify]

For reasons I admit I do not understand, the deprecation warnings for StaticSingleThreadedExecutor on Windows happen when we construct a shared_ptr for it in the tests. If we construct a regular object, then it is fine. Luckily this test does not require a shared_ptr, so just make it a regular object here, which fixes the warning.

While we are in here, make all of the tests camel case to be consistent.

This should fix the warnings introduced by #2683 . @jmachowinski @fujitatomoya FYI

---

This is an automatic backport of pull request #2692 done by Mergify.

[mergify]

Cherry-pick of 3310f9e has failed:

On branch mergify/bp/jazzy/pr-2692
Your branch is up to date with 'origin/jazzy'.

You are currently cherry-picking commit 3310f9ea.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   rclcpp/test/rclcpp/executors/test_executors.cpp

no changes added to commit (use "git add" and/or "git commit -a")

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally

[fujitatomoya]

lgtm with green CI

[fujitatomoya]

Pulls: #2694
Gist: https://gist.githubusercontent.com/fujitatomoya/b421bc8de31710efb855f13ee721174d/raw/563ee7b67742e0d34851f03293c1e400ce11646b/ros2.repos
BUILD args: --packages-above-and-dependencies rclcpp
TEST args: --packages-above rclcpp
ROS Distro: jazzy
Job: ci_launcher
ci_launcher ran: https://ci.ros2.org/job/ci_launcher/14904

• Linux
• Linux-aarch64
• Linux-rhel
• Windows