refactor: Remove sticky disk management while keeping build reporting

- Remove sticky disk mounting and unmounting logic
- Remove sticky disk commit logic from both main and post actions
- Replace setupStickyDisk with reportBuildStart to only report build start
- Update build completion reporting to not depend on exposeId
- Keep build tracking and reporting functionality intact

The sticky disk lifecycle is now fully managed by setup-docker-builder

src/setup_builder.ts

@@ -329,6 +329,16 @@ const stickyDiskTimeoutMs = 45000;
 
 // setupStickyDisk mounts a sticky disk for the entity and returns the device information.
 // throws an error if it is unable to do so because of a timeout or an error
+export async function reportBuildStart(dockerfilePath: string): Promise<{docker_build_id: string} | null> {
+  try {
+    const buildResponse = await reporter.reportBuild(dockerfilePath);
+    return buildResponse;
+  } catch (error) {
+    core.warning(`Error reporting build start: ${(error as Error).message}`);
+    return null;
+  }
+}
+
 export async function setupStickyDisk(dockerfilePath: string, setupOnly: boolean): Promise<{device: string; buildId?: string | null; exposeId: string}> {
   try {
     const controller = new AbortController();