Dockerfile & Docs: Change bitbucket.org/nuttx/tools to github.com/patacongo/tools

[lupyuen]

Summary

The repo bitbucket.org/nuttx/tools is no longer available. This PR changes it to to github.com/patacongo/tools, as explained in #18890. This PR updates the URL in Dockerfile and Docs.

Impact

Dockerfile now builds correctly. Previously the Dockerfile build failed like this:

Dockerfile:53
--------------------
  52 |     RUN mkdir -p /tools/nuttx-tools
  53 | >>> RUN curl -s -L https://bitbucket.org/nuttx/tools/get/9ad3e1ee75c7.tar.gz \
  54 | >>>   | tar -C nuttx-tools --strip-components=1 -xz
  55 |     
--------------------
ERROR: failed to build: failed to solve: process "/bin/sh -c curl -s -L https://bitbucket.org/nuttx/tools/get/9ad3e1ee75c7.tar.gz   | tar -C nuttx-tools --strip-components=1 -xz" did not complete successfully: exit code: 2

https://github.com/apache/nuttx/actions/runs/26381245708/job/77650769793?pr=18953

Testing

This URL change has been tested earlier in #18890