CI: Add testrmsenv.sh script for testing against RMS environment

[AdilKhurshid]

Resolves #361
https://github.com/equinor/rms-sys/issues/361

Added ci/testrmsenv.sh to enable validation of newly built RMS environments by running its unit tests against them.

Checklist

• Tests added (if not, comment why)
• Test coverage equal or up from main (run pytest with --cov=src/ --cov-report term-missing)
• If not squash merging, every commit passes tests
• Appropriate commit prefix and precise commit message used
• All debug prints and unnecessary comments removed
• Docstrings are correct and updated
• Documentation is updated, if necessary
• Latest main rebased/merged into branch
• Added comments on this PR where appropriate to help reviewers
• Moved issue status on project board
• Checked the boxes in this checklist ✅

[GibranAlfa]

i think we should not use uv here, as like we did in other testrmsenv.sh in https://github.com/equinor/xtgeo/blob/main/ci/testrmsenv.sh for example,, uv might not resolve the correct python from RMS env

[AdilKhurshid]

i think we should not use uv here, as like we did in other testrmsenv.sh in https://github.com/equinor/xtgeo/blob/main/ci/testrmsenv.sh for example,, uv might not resolve the correct python from RMS env

Done

[GibranAlfa]

The xtgeoviz tests still resolve testdata through ../xtgeo-testdata in several places, and in the rms-sys workflow pytest runs from $CI_ROOT/xtgeoviz_test_root while the cached testdata lives at $XTGEO_TESTDATA_PATH. We can add a symlink from $CI_ROOT/xtgeo-testdata to $XTGEO_TESTDATA_PATH before running pytest. The --testdatapath argument is accepted, but it is not used by all xtgeoviz tests.

Suggested change

	cp -r $PROJECT_ROOT/tests $CI_TEST_ROOT
	ln -s $XTGEO_TESTDATA_PATH $CI_ROOT/xtgeo-testdata
	cp -r $PROJECT_ROOT/tests $CI_TEST_ROOT

[AdilKhurshid]

Done