[IsaacLab CI] Add light weight post-merge integration tests

[mataylor-nvidia]

Description

All other tests are treated as a part of the full suite and do not get run on push only the following:

rendering-correctness (~20m)
rendering-correctness-kitless (~20m)

A subset of these rendering tests were added to the toml which are stable.

Type of change

• New feature (non-breaking change which adds functionality)

Checklist

• I have read and understood the contribution guidelines
• I have run the pre-commit checks with ./isaaclab.sh --format
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• I have updated the changelog and the corresponding version in the extension's config/extension.toml file
• I have added my name to the CONTRIBUTORS.md or my name already exists there

[greptile-apps]

Greptile Summary

This PR adds a post-merge CI path for pushes to protected branches (main, develop, release/**), running only the two rendering-correctness jobs (~20 min each) instead of the full ~400-minute test matrix. The CI_IMAGE_TAG for non-PR events now uses run-{run_id} instead of github.ref_name, avoiding forward-slash characters in tags from release/x.y.z branches. continue-on-error on the rendering jobs is changed from a hard true to false on push so failures actually block the merge-gate signal.

• All heavy test jobs (test-isaaclab-*, test-curobo, test-environments-training, etc.) gain github.event_name != 'push' guards so they are skipped on push events.
• test-rendering-correctness and test-rendering-correctness-kitless remain ungated and will execute on every push to a protected branch; continue-on-error is false for push so a rendering failure marks the workflow as failed.
• The changes job unconditionally sets run_docker_tests=true for all non-PR events, meaning the Docker base build and rendering tests fire on every push regardless of which paths changed.

Confidence Score: 5/5

The change is a CI-only addition that introduces a push trigger for protected branches and limits post-merge runs to two rendering tests. No application code is modified.

The workflow logic is internally consistent: the base build runs on push, all heavy test jobs are correctly gated with github.event_name != 'push', and the rendering jobs are the only ones that execute post-merge. The CI_IMAGE_TAG fix from ref_name to run_id eliminates a latent slash-in-tag bug for release branches. The continue-on-error expression correctly handles PR, push, and workflow_dispatch as three separate cases.

No files require special attention — the single modified file is .github/workflows/build.yaml and its changes are consistent throughout.

Important Files Changed

Filename	Overview
.github/workflows/build.yaml	Adds a push trigger for protected branches, gates all heavy test jobs with github.event_name != 'push', and changes continue-on-error on rendering jobs to be strict on push. Image tag changed from ref_name to run_id for non-PR events to avoid slash characters.

_{Reviews (4): Last reviewed commit: "fix" | Re-trigger Greptile}

[mataylor-nvidia]

@greptileai