Add Java and Kotlin protobuf bindings #4

	name: JVM bindings

	# The Java and Kotlin bindings are built with Maven directly rather than
	# Nix because scip-kotlin depends on scip-java as a Maven artifact, which
	# nixpkgs' offline `maven.buildMavenPackage` sandbox cannot resolve from
	# the sibling derivation. A regular `mvn install` -> `mvn package` flow
	# in a single CI job is simpler and more reliable.

	on:
	pull_request:
	paths:
	- bindings/java/**
	- bindings/kotlin/**
	- cmd/scip/version.txt
	- scip.proto
	- .github/workflows/jvm-bindings.yaml

	permissions:
	contents: read

	concurrency:
	group: jvm-bindings-${{ github.head_ref \|\| github.ref }}
	cancel-in-progress: true

	jobs:
	build:
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@v6

	- uses: actions/setup-java@v5
	with:
	distribution: temurin
	java-version: 11
	cache: maven

	- name: Validate pom.xml versions match cmd/scip/version.txt
	shell: python
	run: \|
	import xml.etree.ElementTree as ET
	expected = open('cmd/scip/version.txt').read().strip()
	for pom in 'bindings/java/pom.xml', 'bindings/kotlin/pom.xml':
	actual = ET.parse(pom).getroot().findtext('{http://maven.apache.org/POM/4.0.0}version')
	assert actual == expected, f'{pom}: version is {actual!r}, expected {expected!r}'

	- name: Build scip-java and install to local Maven repo
	run: mvn -B -ntp -f bindings/java/pom.xml install

	- name: Build scip-kotlin (resolves scip-java from local repo)
	run: mvn -B -ntp -f bindings/kotlin/pom.xml package

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