Pin pvxs to earlier version

[evalott100]

When pandablocks-ioc uses softioc version 4.5.0, the following import error occurs:

.venv) [twj43146@pc0139 PandABlocks-ioc-fork]$ pytest
filename="modules/database/src/ioc/dbStatic/dbLexRoutines.c" line number=276dbRead opening file pvxsIoc.dbd
ImportError while loading conftest '/scratch/twj43146/Programming/PandABlocks-ioc-fork/tests/conftest.py'.
tests/conftest.py:3: in <module>
    from fixtures.mocked_panda import *
tests/fixtures/mocked_panda.py:38: in <module>
    from softioc import builder
.venv/lib/python3.10/site-packages/softioc/__init__.py:25: in <module>
    dbLoadDatabase('pvxsIoc.dbd', pvxslibs.path.dbd_path, None)
.venv/lib/python3.10/site-packages/softioc/imports.py:45: in expect_success
    assert status == 0, 'Expected success'
E   AssertionError: Expected success

This is caused by the latest release of pvxs.

Pinning "pvxslibs==1.2.4" fixes this problem.

@AlexanderWells-diamond, am I good to do this?

[AlexanderWells-diamond]

This isn't so clear cut unfortunately. The issue is that we cannot load pvxsIoc.dbd anymore, which used to be shipped with pvsxlibs. Now there are two dbd files shipped: pvxs3x.dbd and pvxs7x.dbd (seen in pvxslibs/dbd in an installed version or in pvsxlibs/ioc if looking at sources)

I'm inclined to say that we should instead be loading pvxs7x.dbd, as we are built against R7.0.7 (due to epicscorelibs dependency). I don't know enough about pvxs to know if this may cause other problems though - @coretl, does using the R7 version make the most sense?

[coretl]

yes

[AlexanderWells-diamond]

No longer necessary - see #146 .