Update checkout command to use release branch

[sagerkudrick]

install_dependencies.sh exists in the release/1.5.3b2 branch not main

Motivation

install_dependencies.sh doesn't exist in main, theirs has requirements.txt and requires the user to pip install -r requirements.txt rather than executing this script. ROCm install differs from the modern NVIDIA install

Furthermore, release/1.5.3b2's main/examples is 552 commits ahead of main

Technical Details

Test Plan

Test Result

./install_dependencies.sh fails because the file doesn't exist.
If you instead use pip install -r requirements.txt that main assumes, you get an incorrect installation as release/1.5.3b2 includes:
pip install git+https://github.com/rahul-goel/fused-ssim/@88169c51c22973ad8fd2429c3298d8356fdd5dc8 --no-build-isolation

Submission Checklist

• Look over the contributing guidelines at https://github.com/ROCm/ROCm/blob/develop/CONTRIBUTING.md#pull-requests.

[sagerkudrick]

Just following up on this PR. The instructions differ between main and release/1.5.3b2, so I aligned the README with the release branch behavior.

Let me know if the intended target should instead be updated to match main, happy to adjust