Fix release tarball base version naming

[tuhaihe]

For RC tags like X.Y.Z-incubating-rcN, generate the source tarball filename and top-level directory using VERSION_FILE (without -rcN).

$VERSION_FILE is input from the file VERSION.

This keeps the voted bits ready for promotion without rebuilding and avoids -rcN showing up in the extracted source directory.

closes: #ISSUE_Number

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[robertmu]

It seems like that the top-level extracted directory now uses VERSION_FILE, but the tarball filename still uses TAG (TAR_NAME="apache-cloudberry-backup-${TAG}-src.tar.gz"). If the intent is to remove -rcN from both directory and filename, Should we also switch TAR_NAME to use VERSION_FILE?