[CI] Pinning tree-sitter-cpp version to fix CI errors (#879)

## Summary of Changes
A recent update to the tree-sitter-cpp repository has broken
compatibility with the tree-sitter version we are using. This PR pins
the tree-sitter-cpp version to the last working commit.

skema/program_analysis/tree_sitter_parsers/languages.yaml

@@ -9,6 +9,7 @@ c:
 cpp:
   tree_sitter_name: tree-sitter-cpp
   clone_url: https://github.com/tree-sitter/tree-sitter-cpp.git
+  commit_sha: e0c1678
   supports_comment_extraction: True
   supports_fn_extraction: False
   extensions: