pylint 3.0.0 reports cyclic-import errors

[seisman]

First reported in #2709 (comment).

With the latest pylint 3.0.0 (https://github.com/pylint-dev/pylint/releases/tag/v3.0.0), the style checks workflow now reports the following errors:

Run make lint
pylint pygmt doc/conf.py
************* Module conf
doc/conf.py:1:0: R0401: Cyclic import (pygmt -> pygmt.src -> pygmt.src.timestamp) (cyclic-import)
doc/conf.py:1:0: R0401: Cyclic import (pygmt -> pygmt.src -> pygmt.src.ternary) (cyclic-import)
doc/conf.py:1:0: R0401: Cyclic import (pygmt -> pygmt.figure -> pygmt.src.timestamp) (cyclic-import)
doc/conf.py:1:0: R0401: Cyclic import (pygmt -> pygmt.figure -> pygmt.src.ternary) (cyclic-import)

-----------------------------------
Your code has been rated at 9.99/10

make: *** [Makefile:79: lint] Error 8
Error: Process completed with exit code 2.

The cyclic-import errors are caused by the __gmt_version__ variable added in #2366.