dbSta: conditionally enable OpenSTA analysis_corner support

[dsengupta0628]

Summary

The OpenROAD fork of OpenSTA adds an analysis_corner feature (per-corner SDC, liberty/spef bundles); stock parallaxsw OpenSTA does not have it. This change exposes the feature in the openroad binary without breaking builds against stock OpenSTA:

• dbSta.i: includes search/AnalysisCorner.i behind an STA_HAS_ANALYSIS_CORNER guard.
• CMake: probes for the file in the OpenSTA submodule; when present, sets the guard and embeds tcl/AnalysisCorner.tcl. With stock OpenSTA the probe fails and the build is unchanged.
• Bazel: sets the guard via swig_options (the pinned submodule is the fork; remove the define if swapping in stock OpenSTA — Bazel cannot probe file existence).

With the fork submodule, corner commands work in openroad; with stock OpenSTA, openroad builds and behaves exactly as today. The fork's Tcl also degrades gracefully in any binary lacking the swig module (guards pass through), so a mismatched combination fails soft rather than breaking SDC commands.

Type of Change

• New feature

Impact

Allows using new commands in The-OpenROAD-Project/OpenSTA#394

Verification

• I have verified that the local build succeeds (./etc/Build.sh).
• I have run the relevant tests and they pass.
• My code follows the repository's formatting guidelines.
• I have included tests to prevent regressions.
• I have signed my commits (DCO).

[gemini-code-assist]

Code Review

This pull request updates the src/sta submodule and introduces conditional support for AnalysisCorner in dbSta. It adds build configuration checks in CMakeLists.txt and BUILD to define STA_HAS_ANALYSIS_CORNER and include AnalysisCorner.i and AnalysisCorner.tcl only when they are available in the OpenSTA submodule, ensuring compatibility with stock OpenSTA. I have no feedback to provide.