Fix crash and loose matching in adjustver.py version parser

[jacquelinegarrahan]

Fix crash and loose matching in adjustver.py version parser

Branch: fix/adjustver-version-parsing → master

Summary

.tools/adjustver.py parses a version string passed via -V/--version into
the EPICS_*_VERSION macros written to configure/CONFIG_*_VERSION. The parser
had two defects:

1. Unguarded re.match result → uncaught traceback. The result of
   re.match(...) was indexed directly (M[2], M[3], …) with no None
   check. Any version string that failed to match crashed with:

   TypeError: 'NoneType' object is not subscriptable
   

   instead of a usable diagnostic.

2. Unescaped . in the pattern. r'R?(\d+).(\d+).(\d+)(?:.(\d+))?(-.*)?'
   used bare ., which matches any character, so malformed inputs such as
   R7x0x10 were silently accepted as if valid.

Fix

.tools/adjustver.py:

• Escape the separators and anchor the pattern:
  r'R?(\d+)\.(\d+)\.(\d+)(?:\.(\d+))?(-.*)?$'
• Add a None check that prints a clear message and sys.exit(1) when the
  version cannot be parsed.

Verification

# before (master): crashes
$ python3 .tools/adjustver.py -V garbage -n configure/CONFIG_BASE_VERSION
    ('MINOR_VERSION', M[2]),
TypeError: 'NoneType' object is not subscriptable

# after (this branch): clean error, exit 1
$ python3 .tools/adjustver.py -V garbage -n configure/CONFIG_BASE_VERSION
Unable to parse version 'garbage'; expected e.g. R1.2.3, 1.2.3, or 1.2.3.4-suffix

# valid input unchanged
$ python3 .tools/adjustver.py -V R7.0.10.1-DEV -n configure/CONFIG_BASE_VERSION
EPICS_VERSION = 7 ... EPICS_MODIFICATION = 10 ... (DEV snapshot handled)

Risk

Low. Behavior is unchanged for every well-formed version string; only
previously-malformed inputs change from "crash / silently mis-parse" to
"explicit error".