pick-kotlin-version.py: tolerate warnings

[cklin]

This PR changes pick-kotlin-version.py to use re.search() instead of re.match(), so that it can better cope with warning messages.

Running pick-kotlin-version.py with JRE 24, without this PR:

Traceback (most recent call last):
  File "codeql/java/kotlin-extractor/pick-kotlin-version.py", line 31, in <module>
    raise Exception(f'Cannot detect version of kotlinc (got {res.stderr})')
Exception: Cannot detect version of kotlinc (got WARNING: A restricted method in java.lang.System has been called
WARNING: java.lang.System::load has been called by org.fusesource.jansi.internal.JansiLoader in an unnamed module
WARNING: Use --enable-native-access=ALL-UNNAMED to avoid a warning for callers in this module
WARNING: Restricted methods will be blocked in a future release unless native access is enabled

info: kotlinc-jvm 2.2.0 (JRE 24.0.1)
WARNING: A terminally deprecated method in sun.misc.Unsafe has been called
WARNING: sun.misc.Unsafe::objectFieldOffset has been called by com.intellij.util.containers.Unsafe
WARNING: Please consider reporting this to the maintainers of class com.intellij.util.containers.Unsafe
WARNING: sun.misc.Unsafe::objectFieldOffset will be removed in a future release
)

Running pick-kotlin-version.py with JRE 24, with this PR:

2.2.0

[Copilot]

Pull Request Overview

This PR updates the Kotlin version detection script to use re.search() instead of re.match(), allowing it to find the version string even when warning lines precede it.

• Switch from re.match() to re.search() in the version regex
• Simplify the regex by removing leading/trailing wildcard matches
• Preserve existing exception handling for parsing failures

Comments suppressed due to low confidence (1)

java/kotlin-extractor/pick-kotlin-version.py:29

• Add a unit test for pick-kotlin-version.py that simulates kotlinc -version output containing warning lines before the version string, to ensure the regex continues to match correctly.

m = re.search(r' kotlinc-jvm ([0-9]+\.[0-9]+\.[0-9]+(-[a-zA-Z][a-zA-Z0-9]*)?) ', res.stderr)

[Copilot]

Improve the regex to use word boundaries and flexible whitespace, e.g. r"\bkotlinc-jvm\s+([0-9]+\.[0-9]+\.[0-9]+(?:-[A-Za-z][A-Za-z0-9]*)?)\b", to make it more robust against punctuation or line breaks.

Suggested change

	m = re.search(r' kotlinc-jvm ([0-9]+\.[0-9]+\.[0-9]+(-[a-zA-Z][a-zA-Z0-9]*)?) ', res.stderr)
	m = re.search(r"\bkotlinc-jvm\s+([0-9]+\.[0-9]+\.[0-9]+(?:-[A-Za-z][A-Za-z0-9]*)?)\b", res.stderr)

[igfoo]

I'm not sure if these warnings indicate that something else will break, but from the Kotlin side it looks fine.