fix(NetworkUDP): flush network UDP - reset tx len to zero

[Guihgo]

By completing this PR sufficiently, you help us to review this Pull Request quicker and also help improve the quality of Release Notes

Checklist

1. Please provide specific title of the PR describing the change, including the component name (eg. „Update of Documentation link on Readme.md“)
2. Please provide related links (eg. Issue which will be closed by this Pull Request)
3. Please update relevant Documentation if applicable
4. Please check Contributing guide
5. Please confirm option to "Allow edits and access to secrets by maintainers" when opening a Pull Request

This entire section above can be deleted if all items are checked.

---

Description of Change

Fix flush network UDP method

Tests scenarios

I have tested my Pull Request on Arduino-esp32 core 3.1.3 +IDF 5.3.2 with ESP32 and ESP32-S2 Board and ESP32-CAM with this scenario

[CLAassistant]

All committers have signed the CLA.

[github-actions]

Warnings

⚠️

Some issues found for the commit messages in this PR: the commit message "[fix] flush network UDP - set tx len to zero": summary looks empty type/action looks empty Please fix these commit messages - here are some basic tips: follow Conventional Commits style correct format of commit message should be: <type/action>(<scope/component>): <summary>, for example fix(esp32): Fixed startup timeout issue allowed types are: change,ci,docs,feat,fix,refactor,remove,revert,test sufficiently descriptive message summary should be between 10 to 72 characters and start with upper case letter avoid Jira references in commit messages (unavailable/irrelevant for our customers) TIP: Install pre-commit hooks and run this check when committing (uses the Conventional Precommit Linter).

👋 Hello Guihgo, we appreciate your contribution to this project!

---

📘 Please review the project's Contributions Guide for key guidelines on code, documentation, testing, and more.

---

🖊️ Please also make sure you have read and signed the Contributor License Agreement for this project.

---

Click to see more instructions ...

This automated output is generated by the PR linter DangerJS, which checks if your Pull Request meets the project's requirements and helps you fix potential issues.

DangerJS is triggered with each push event to a Pull Request and modify the contents of this comment.

Please consider the following:
- Danger mainly focuses on the PR structure and formatting and can't understand the meaning behind your code or changes.
- Danger is not a substitute for human code reviews; it's still important to request a code review from your colleagues.
- Resolve all warnings (⚠️ ) before requesting a review from human reviewers - they will appreciate it.
- To manually retry these Danger checks, please navigate to the Actions tab and re-run last Danger workflow.

Review and merge process you can expect ...

We do welcome contributions in the form of bug reports, feature requests and pull requests.

1. An internal issue has been created for the PR, we assign it to the relevant engineer.
2. They review the PR and either approve it or ask you for changes or clarifications.
3. Once the GitHub PR is approved we do the final review, collect approvals from core owners and make sure all the automated tests are passing.
- At this point we may do some adjustments to the proposed change, or extend it by adding tests or documentation.
4. If the change is approved and passes the tests it is merged into the default branch.

Generated by 🚫 dangerJS against d6c97f8

[tonhuisman]

Indentation style in this file is using 2 spaces, please don't change that.

[github-actions]

Test Results

 76 files   76 suites   12m 58s ⏱️
 38 tests  38 ✅ 0 💤 0 ❌
241 runs  241 ✅ 0 💤 0 ❌

Results for commit d6c97f8.