Update testcontainer.version to v1.20.3

This MR contains the following updates:

Package	Type	Update	Change
org.testcontainers:postgresql (source)	test	patch	1.20.2 -> 1.20.3
org.testcontainers:junit-jupiter (source)	test	patch	1.20.2 -> 1.20.3

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Release Notes

testcontainers/testcontainers-java (org.testcontainers:postgresql)

v1.20.3

Compare Source

What's Changed

• Pin OceanBase image (#​9416) @​eddumelendez
• Fix execution in windows runner (#​9413) @​eddumelendez

🚀 Features & Enhancements

• Log exception on socket problems (#​8055) @​ciis0
• Add support for apachepulsar/pulsar-all image (#​9448) @​eddumelendez
• Introduce new property to configure pull.timeout (#​9417) @​eddumelendez
• Add r2dbc support for Clickhouse (#​8434) @​livk-cloud
• Support reset value in Docker Compose (#​9343) @​eddumelendez

🐛 Bug Fixes

• fix: await during DockerClientProviderStrategy test method (#​9412) @​KyleAure
• Parse docker compose file correctly when version is not declared (#​9420) @​eddumelendez
• Read docker credentials stdout and stderr independently (#​8007) @​Smeb
• Use server URL from auth query if helper does not return one (#​9056) @​eager-signal
• Clear docker compose initialization (#​9370) @​eddumelendez

📖 Documentation

• Add "integration-testing" topic (#​9338) @​bsideup

🧹 Housekeeping

• Declarative R2DBC SPI implementation (#​9447) @​eddumelendez
• Fix windows test (#​9409) @​eddumelendez
• Add ComposeContainer test to junit-jupiter module (#​9407) @​eddumelendez
• Check docker compose version (#​9342) @​eddumelendez
• Use Awaitility in FixedHostPortContainerTest (#​9341) @​eddumelendez
• Polish Kafka examples (#​9340) @​eddumelendez
• Polish Cassandra tests (#​9339) @​eddumelendez

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