fix(deps): update module github.com/kcp-dev/kcp/sdk to v0.28.3

Author: renovate[bot]

go.mod

@@ -9,7 +9,7 @@ require (
 	github.com/fluxcd/helm-controller/api v1.4.2
 	github.com/fluxcd/source-controller/api v1.7.2
 	github.com/go-logr/logr v1.4.3
-	github.com/kcp-dev/kcp/sdk v0.28.1-0.20250926104223-cec2e15f24c6
+	github.com/kcp-dev/kcp/sdk v0.28.3
 	github.com/kcp-dev/logicalcluster/v3 v3.0.5
 	github.com/kcp-dev/multicluster-provider v0.2.0
 	github.com/openfga/api/proto v0.0.0-20250909173124-0ac19aac54f2

go.sum

@@ -110,8 +110,8 @@ github.com/json-iterator/go v1.1.12 h1:PV8peI4a0ysnczrg+LtxykD8LfKY9ML6u2jnxaEnr
 github.com/json-iterator/go v1.1.12/go.mod h1:e30LSqwooZae/UwlEbR2852Gd8hjQvJoHmT4TnhNGBo=
 github.com/kcp-dev/apimachinery/v2 v2.0.1-0.20250728122101-adbf20db3e51 h1:l38RDS+VUMx9etvyaCgJIZa4nM7FaNevNubWN0kDZY4=
 github.com/kcp-dev/apimachinery/v2 v2.0.1-0.20250728122101-adbf20db3e51/go.mod h1:rF1jfvUfPjFXs+HV/LN1BtPzAz1bfjJOwVa+hAVfroQ=
-github.com/kcp-dev/kcp/sdk v0.28.1-0.20250926104223-cec2e15f24c6 h1:bOR4mdLD24VCJRrHxmtTh21AdbbzkBBKkEh0ngL+XTc=
-github.com/kcp-dev/kcp/sdk v0.28.1-0.20250926104223-cec2e15f24c6/go.mod h1:aC2BPGPvy8QtkI2gQNH9NfW6xpfGIKZkR93gy9O02BE=
+github.com/kcp-dev/kcp/sdk v0.28.3 h1:TS2nJOVBjenBd3fz1+y3aNrqZWqmakalNAIcQM9SukQ=
+github.com/kcp-dev/kcp/sdk v0.28.3/go.mod h1:8oZpWxkoMu2TDpx5DgdIGDigByKHKkeqVMA4GiWneoI=
 github.com/kcp-dev/logicalcluster/v3 v3.0.5 h1:JbYakokb+5Uinz09oTXomSUJVQsqfxEvU4RyHUYxHOU=
 github.com/kcp-dev/logicalcluster/v3 v3.0.5/go.mod h1:EWBUBxdr49fUB1cLMO4nOdBWmYifLbP1LfoL20KkXYY=
 github.com/kcp-dev/multicluster-provider v0.0.0-20250827085327-2b5ca378b7b4 h1:GUihV22j2J/cGF5Svr/zGVvfqTJepIO+sOnYTn9o4Vc=