ci: disable pip/venv DB migration test while langflow-nightly is pip-uninstallable

The PyPI langflow-nightly is currently pip-uninstallable: its core bundle
deps (lfx-arxiv, lfx-duckduckgo) pin stable lfx>=0.5.0,<0.6.0, but stable
lfx tops out at 0.4.4 (the 0.5.0 line ships only as lfx-nightly, a separate
package name that cannot satisfy an lfx pin). So the pip/venv migration job
fails at the install step.

The Docker Compose migration job is unaffected (it runs the prebuilt nightly
image) and stays enabled. Re-enable once either a stable lfx 0.5.x is
published to PyPI or nightly bundle variants pinning lfx-nightly are
published and langflow-nightly depends on them.

Author: erichare

.github/workflows/db-migration-validation.yml

@@ -25,6 +25,17 @@ env:
 jobs:
   migration-pip-venv:
     name: "Migration Test: pip/venv (stable → nightly)"
+    # TEMPORARILY DISABLED (2026-05-28): the PyPI `langflow-nightly` is currently
+    # pip-uninstallable. Its core bundle deps (lfx-arxiv, lfx-duckduckgo) are
+    # published pinning stable `lfx>=0.5.0,<0.6.0`, but stable `lfx` tops out at
+    # 0.4.4 — the 0.5.0 line ships only as the separately-named `lfx-nightly`,
+    # which cannot satisfy an `lfx` pin. So this job fails at the install step.
+    # The Docker Compose job below is unaffected (it runs the prebuilt nightly
+    # image, whose environment is already resolved). Re-enable once EITHER a
+    # stable lfx 0.5.x is published to PyPI OR nightly bundle variants (e.g.
+    # lfx-arxiv-nightly pinning lfx-nightly) are published and langflow-nightly
+    # depends on them.
+    if: false
     runs-on: ubuntu-latest
     timeout-minutes: 30