SSoggySouls for Hardcore

fix(fabric): fix empty remapJar by merging common classes directly

• Remove include project(':common') JiJ embed. Loom's processIncludeJars requires valid semver on all JiJ deps; common has version=unspecified, causing Loom to silently drop the embed and produce a 308-byte empty remapJar JAR.
• Add from(project(':common').sourceSets.main.output) to the jar task instead, directly merging common classes into the Fabric JAR \u2014 the same pattern Forge already uses.
• All DB libs (HikariCP, MySQL, SQLite) remain as JiJ embeds via their existing include implementation(...) declarations.
• Add --no-build-cache to CI gradlew invocation to prevent stale cached remapJar outputs from being restored.