Bump version to 1.12.3 (#7429)

This PR bumps version to 1.12.3 for preparation of the next release.

Signed-off-by: Yong Tang <yong.tang.github@outlook.com>

coremain/version.go

@@ -2,7 +2,7 @@ package coremain
 
 // Various CoreDNS constants.
 const (
-	CoreVersion = "1.12.2"
+	CoreVersion = "1.12.3"
 	CoreName    = "CoreDNS"
 	serverType  = "dns"
 )

notes/coredns-1.12.3.md

@@ -0,0 +1,45 @@
++++
+title = "CoreDNS-1.12.3 Release"
+description = "CoreDNS-1.12.3 Release Notes."
+tags = ["Release", "1.12.3", "Notes"]
+release = "1.12.3"
+date = "2024-07-30T00:00:00+00:00"
+author = "coredns"
++++
+
+This release improves plugin reliability and standards compliance, adding startup timeout to the Kubernetes
+plugin, fallthrough to gRPC, and EDNS0 unset to rewrite. The file plugin now preserves SRV record case per
+RFC 6763, route53 is updated to AWS SDK v2, and multiple race conditions in cache and connection handling in
+forward are fixed.
+
+## Brought to You By
+
+blakebarnett
+Cameron Steel
+Dave Brown
+Dennis Simmons
+harshith-2411-2002
+houpo-bob
+Oleg Guba
+Sebastian Mayr
+Stephen Kitt
+Syed Azeez
+Ville Vesilehto
+Yong Tang
+Yoofi Quansah
+
+
+## Noteworthy Changes
+
+* plugin/auto: Return REFUSED when no next plugin is available (https://github.com/coredns/coredns/pull/7381)
+* plugin/cache: Create a copy of a response to ensure original msg is never modified (https://github.com/coredns/coredns/pull/7357)
+* plugin/cache: Fix data race when refreshing cached messages (https://github.com/coredns/coredns/pull/7398)
+* plugin/cache: Fix data race when updating the TTL of cached messages (https://github.com/coredns/coredns/pull/7397)
+* plugin/file: Return REFUSED when no next plugin is available (https://github.com/coredns/coredns/pull/7381)
+* plugin/file: Preserve case in SRV record names and targets per RFC 6763 (https://github.com/coredns/coredns/pull/7402)
+* plugin/forward: Handle cached connection closure in forward plugin (https://github.com/coredns/coredns/pull/7427)
+* plugin/grpc: Add support for fallthrough to the grpc plugin (https://github.com/coredns/coredns/pull/7359)
+* plugin/kubernetes: Add startup_timeout for kubernetes plugin (https://github.com/coredns/coredns/pull/7068)
+* plugin/rewrite: Add EDNS0 unset action (https://github.com/coredns/coredns/pull/7380)
+* plugin/route53: Port to AWS Go SDK v2 (https://github.com/coredns/coredns/pull/6588)
+* plugin/test: Fix TXT record comparison logic for multi-string vs multi-record scenarios (https://github.com/coredns/coredns/pull/7413)