Bump version to 0.4.0-RC.2 [skip ci]

RecordFilesPostgres refused every Amazon Aurora PostgreSQL database: Aurora
reports full_page_writes = off (measured on engine 17.9) and the parameter is
not in the cluster parameter group, so it cannot be changed. Its storage layer
does not write torn pages, so the protection that setting gives stock
PostgreSQL is not needed there.

The settings query now carries a twelfth column,
to_regprocedure('aurora_version()') IS NOT NULL, which is true on Aurora and
false on stock PostgreSQL without raising. full_page_writes = off is accepted
only when that column is true. Stock PostgreSQL with full_page_writes = off is
still refused, and fsync, synchronous_commit, the writable primary, version,
UTC, READ COMMITTED, the lock_timeout bound and every owner-table check are
unchanged on both.

Tests: PostgresDurabilityRuleTest (pure rule, every build) and
PostgresAuroraQualificationTest (opt-in, real PostgreSQL 17, Aurora simulated
by a test-only aurora_version() function and ALTER SYSTEM full_page_writes).

Co-Authored-By: Claude Fable 5.2 <noreply@anthropic.com>

pom.xml

@@ -18,7 +18,7 @@
 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 
    <properties>
-      <revision>0.5.0-SNAPSHOT</revision>
+      <revision>0.4.0-RC.2</revision>
       <maven.compiler.source>21</maven.compiler.source>
       <maven.compiler.target>21</maven.compiler.target>
       <jacoco.version>0.8.15</jacoco.version>