[post-migration] google-crc32c: Wire up cross-platform Kokoro release scripts

Properly integrate google-crc32c into the monorepo's Kokoro infrastructure so the C-extension is compiled and tested across all required platforms (Linux, macOS, Windows).

Objective
Properly integrate google-crc32c into the monorepo's Kokoro infrastructure so the C-extension is compiled and tested across all required platforms (Linux, macOS, Windows).

Files to Update / Clean Up:

- Bypass Scripts: * packages/google-crc32c/scripts/bypass.sh (Used for Linux/macOS)

- packages/google-crc32c/scripts/bypass.bat (Used for Windows)

- Kokoro Configs: Update the following files to use the standard monorepo Trampoline/Docker testing patterns instead of calling the bypass scripts:

- .kokoro/presubmit/linux/presubmit-linux.cfg

- .kokoro/presubmit/osx/presubmit-osx.cfg

- .kokoro/presubmit/windows/presubmit-windows.cfg

Tasks

- [ ] Delete the temporary .sh and .bat bypass scripts.

- [ ] Linux: Configure the Kokoro job to properly build the C-extension (ensure Manylinux container compatibility).

- [ ] macOS: Ensure the Kokoro runner correctly compiles the extension natively.

- [ ] Windows: Ensure the Windows Kokoro runner correctly compiles the C-extension using the native Windows build steps.

Related PR for Migration: https://github.com/googleapis/google-cloud-python/pull/16006