Bump version number to 1.23.1 #2547

Job	Run time
License Header and Formatting Checks	3m 1s
Integration Tests on swiftlang/swift:nightly-jammy	4m 20s
Build and Test on swiftlang/swift:nightly-jammy	2m 1s
Integration Tests on swiftlang/swift:nightly-6.0-jammy	9m 43s
Performance Tests on swiftlang/swift:nightly-jammy	2m 59s
Build and Test on swiftlang/swift:nightly-6.0-jammy	7m 7s
Integration Tests on swift:5.10.1-noble	5m 4s
Build and Test on swift:5.10.1-noble	4m 3s
Integration Tests on swift:5.9-jammy	3m 55s
Performance Tests on swiftlang/swift:nightly-6.0-jammy	3m 19s
Build and Test on swift:5.9-jammy	3m 16s
Performance Tests on swift:5.10.1-noble	30s
Integration Tests on swift:5.8-focal	3m 28s
Build and Test on swift:5.8-focal	2m 55s
Performance Tests on swift:5.9-jammy	34s
Performance Tests on swift:5.8-focal	27s
	56m 42s

Provide feedback