chore(package.xml): bump version to 0.38.0 (#1226)

[youtalk]

Description

This PR incorporates changes from the humble branch into the main branch. #1226

This is almost same as autowarefoundation/autoware.universe#9266 but for autoware_launch.

This PR is based on https://github.com/orgs/autowarefoundation/discussions/5292 and aims to manage the versioning of autowarefoundation/autoware_launch using ROS package release tools.
All package versions have been unified to 0.38.0 following https://github.com/tier4/autoware_launch/tree/v0.38.0.

Note that this PR is a merge request not for the main branch, but for the newly created humble branch. Once this PR is merged, I plan to tag 0.38.0 on the humble branch and create a PR to merge the differences into the main branch as well.

Currently, I was manually running the ROS package release tools to create PR, but in the future, we would like to modify https://github.com/tier4/autoware-release-scripts to automate this process.

Tests performed

Not applicable.

Effects on system behavior

Not applicable.

Interface changes

Pre-review checklist for the PR author

The PR author must check the checkboxes below when creating the PR.

• I've confirmed the contribution guidelines.
• The PR follows the pull request guidelines.

In-review checklist for the PR reviewers

The PR reviewers must check the checkboxes below before approval.

• The PR follows the pull request guidelines.

Post-review checklist for the PR author

The PR author must check the checkboxes below before merging.

• There are no open discussions or they are tracked via tickets.

After all checkboxes are checked, anyone who has write access can merge the PR.