science/cdo: Update MASTER_SITES

• Bump PORTREVISION for potential package change

Regarding cdo 2.5.3, the original tarball is ready around August 13.
The release was announced on August 15 [1].
Upstream silently regenerated the tarball on August 25 [2].

[1] https://code.mpimet.mpg.de/projects/cdo/activity?from=2025-08-15
[2] https://code.mpimet.mpg.de/projects/cdo/files

PR: 289437
Reported by: Robert Kruus <rob.kruus@gmail.com>