Enable core.longpaths on baseline clone to fix Windows MAX_PATH error

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: msyyc

.chronus/changes/fix-regen-baseline-path-2026-5-20.md

@@ -4,4 +4,4 @@ packages:
   - "@typespec/http-client-python"
 ---
 
-Update the baseline source for regeneration to use the `typespec-python-generated-tests` branch and `eng/tools/azure-sdk-tools/emitter/generated` path in `azure-sdk-for-python`.
+Update the baseline source for regeneration to use the `typespec-python-generated-tests` branch and `eng/tools/azure-sdk-tools/emitter/generated` path in `azure-sdk-for-python`, and enable `core.longpaths` on the temporary baseline clone to avoid Windows `MAX_PATH` errors during checkout.

packages/http-client-python/eng/scripts/ci/regenerate-common.ts

@@ -708,6 +708,7 @@ export async function prepareBaselineOfGeneratedCode(generatedFolder: string): P
       execSync(cmd, { cwd: tempDir, stdio: ["ignore", "ignore", "inherit"] });
 
     run(`git init`);
+    run(`git config core.longpaths true`);
     run(`git remote add origin ${repoUrl}`);
     run(`git config core.sparseCheckout true`);
     run(`git sparse-checkout init --cone`);