Fix SNAPSHOT metadata: deploy POM and JAR together

[guizmaii]

Summary

• Fix SNAPSHOT dependency resolution failing in Coursier/sbt due to mismatched build numbers between POM and JAR artifacts

Problem

Each mvn deploy:deploy-file call creates a new build number in the SNAPSHOT maven-metadata.xml. The current script deploys POM and JAR as separate calls:

deploy POM     → build 1 (timestamp 231930)
deploy JAR     → build 2 (timestamp 231938)
deploy sources → build 3 (timestamp 231947)
...

Dependency resolvers like Coursier (used by sbt/Scala) pick the JAR's build number from the metadata and then try to find the POM at the same build number. Since the POM was deployed with build number 1 but Coursier looks for it at build number 2, the download returns 404:

# Coursier tries this (JAR's build number):
GET .../duckdb_jdbc-1.5-627976eb-20260211.231938-2.pom  → 404

# But POM is actually here (different build number):
GET .../duckdb_jdbc-1.5-627976eb-20260211.231930-1.pom  → 200

Fix

Deploy the main JAR with -DpomFile=<path> instead of deploying the POM separately. This way Maven publishes both artifacts in a single operation, giving them the same build number and timestamp.

Test plan

• Verify SNAPSHOT artifacts are published correctly after merge
• Verify sbt / Coursier can resolve the SNAPSHOT dependency without errors

[staticlibs]

Thanks! It looks good to me.