[Repo Assist] ci: remove obsolete LLVM install step from CI workflows

This PR was created by Repo Assist, an automated AI assistant.

Problem

Four CI workflow files install LLVM 14.0 via KyleMayes/install-llvm-action, with the comment:

"At the moment needed to support scipy in Python 3.12+"

This step is no longer needed. All scipy versions locked in poetry.lock ship pre-built manylinux_2_17 wheels for Linux x86_64 (which ubuntu-latest satisfies):

Additionally, numba (a core dependency) uses llvmlite which bundles its own LLVM and does not depend on system LLVM.

Fix

Remove the Install LLVM and Clang step from all 4 workflows:

• ci.yml — was conditional on cache miss, adds overhead on cold starts
• ci-install.yml — ran unconditionally on every PR check
• nightly-tests.yml — ran unconditionally on every nightly run
• advanced-on-demand.yml — ran unconditionally on every advanced run

The ci-install.yml and nightly workflows are most impacted: LLVM 14.0 is a ~2 GB download that adds several minutes to every cold-cache CI run for those jobs.

Test Status

Only .github/workflows/*.yml files changed — no Python code affected. Removing LLVM from the install step will not break any Python package installation because all packages have pre-built wheels.

[!WARNING] Protected Files — Push Permission Denied

This was originally intended as a pull request, but the patch modifies protected files. A human must create the pull request manually.

Protected files

• .github/workflows/advanced-on-demand.yml

• .github/workflows/ci-install.yml
• .github/workflows/ci.yml
• .github/workflows/nightly-tests.yml

The push was rejected because GitHub Actions does not have workflows permission to push these changes, and is never allowed to make such changes, or other authorization being used does not have this permission.

# Download the patch from the workflow run
gh run download 32800159041 -n agent -D /tmp/agent-32800159041

# Create a new branch
git checkout -b repo-assist/eng-remove-llvm-ci-20260825-3ac95bcde8d7615e main

# Apply the patch (--3way handles cross-repo patches)
git am --3way /tmp/agent-32800159041/aw-repo-assist-eng-remove-llvm-ci-20260825.patch

# Push the branch and create the pull request
git push origin repo-assist/eng-remove-llvm-ci-20260825-3ac95bcde8d7615e
gh pr create --title '[Repo Assist] ci: remove obsolete LLVM install step from CI workflows' --base main --head repo-assist/eng-remove-llvm-ci-20260825-3ac95bcde8d7615e --repo py-why/dowhy

Generated by Repo Assist, see workflow run. Learn more.

To install this agentic workflow, run

复制

gh aw add githubnext/agentics/workflows/repo-assist.md@11c9a2c442e519ff2b427bf58679f5a525353f76