Update PMIx submodule pointer to latest v4.2.

Commits since last update:

3e827472a2 - Remove man pages
d0b2c2611d - Fix flex detection
8cb6f58fe0 - Bump VERSION to v4.2.1
b0a4339be4 - Enable show_help output on tools
571393b512 - Fix the buildrpm script
81c14d7df0 - Update NEWS for final release
0582c8512d - Cleanup singletion IOF lists
24f5357560 - examples: add a test to simulate open mpi group usage.
9119231a37 - Output IO as singleton, support background commands
032af19345 - Standardize on const char* key
6fc8ee283d - Revert "Silence gcc12 warnings"
3d746a0daf - Silence gcc12 warnings
92ae1c2618 - Need to replace the entire proc in fence with group member
a1d6ae2a05 - Update NEWS/VERSION for rc2
663b67f86a - Fix/implement the group invite support
6607101815 - Do not error out if lib is symlinked to lib64
9c81ebf592 - Separate out pinstalldirs for inclusion by PRRTE
bd64ea7c1f - Fix the tm configure logic
2ed71f17e8 - Minor cleanup of timestamp output
caafc48966 - Fix reference to removed variable
bdb7150142 - Update NEWS with notices and remove unready components
56d5c400ff - Fix make_tarball and remove unused variable
27d332312f - Update the news, version, and exceptions for rc1
43fa0176a4 - Support broader range of output formats
f87c7ef282 - Sort proc arrays to remove order sensitivity and fix multi-node grp info
75928d777b - Coordinate psec modules across pfexec child
db1418d6e6 - Complete implementation of group info exchange
1b58c79bdc - Update GDS/Hash
dde484925a - Fix the GNU CI run
52c475b4aa - Forward stdin to apps directly fork/exec'd by PMIx
013fb830a5 - Return the correct code for register fabric
5630ca841a - Protect "create" macros from zero entries
f345f0e879 - Fix IOF of stdin
25d4f140be - Update tests for picky compilers and one place in MCA base
fc25381018 - Disable picky compilers in dstore
c5445edb02 - Update VERSION
035155ef50 - Minor touchups for picky compilers
487b139086 - Update the dmodex example
d899119873 - Stop multiple invocations of debugger-release
dcf6fb96e9 - src/include/Makefile.am: avoid potential file corruption
266f6458ae - construct_dictionary.py: make .format() safe for Python 2
977e392ed9 - Cleanup some debug output
487f68d66d - Add "const" qualifiers to some string print APIs
07cdb7dbbc - Fix potential use after free in tests
3c9a3679c6 - Properly cast the list_item_t
cc2ee2eaeb - Fix dmodex operations
a70ce1b0a1 - Fix show_help output to include tools
7ae2993c16 - Update show-help system
54523c3f07 - Fix PMIX_INFO_*PROCESSED macros
09d4463b4e - Remove bad destruct call
c532553236 - Enable pickyness by default in Git repo builds (open-mpi#2631)
be2a27d67c - Return "succeeded" status when outputting help/version info
a3216718ac - Fix pcompress/zlib implementation (open-mpi#2625)
84e1c2319d - Fix typos.
3edfda519f - Add PMIx Standard version info to pmix_info
32ff1b034b - Update the PMIx ABI Query attributes to match the standard
45eaba2284 - Add examples for using PMIx_Query_info with PMIX_QUERY_ABI_VERSION
a978d02e10 - Backend query support for PMIX_QUERY_ABI_VERSION and local keys
52803578fc - Setup PMIX_STD_ABI_VERSION in the VERSION file
7cbe9b67ea - Fix the greek version

Signed-off-by: Austen Lauria <[email protected]>

Author: awlauria