fix: various fixes and features for u15 (#9251)

refs: #9224

## Description

Upgrade our cosmos-sdk fork and cosmos/iavl to pick up bug fixes and
features.

### Security Considerations

See upgrade-15 notes.

### Scaling Considerations

N/A

### Documentation Considerations

N/A - internal changes

### Testing Considerations

See upgrade-15 notes.

### Upgrade Considerations

N/A

golang/cosmos/go.mod

@@ -187,7 +187,10 @@ replace (
 // Agoric-specific replacements:
 replace (
 	// We need a fork of cosmos-sdk until all of the differences are merged.
-	github.com/cosmos/cosmos-sdk => github.com/agoric-labs/cosmos-sdk v0.46.16-alpha.agoric.2.1
+	github.com/cosmos/cosmos-sdk => github.com/agoric-labs/cosmos-sdk v0.46.16-alpha.agoric.2.3
+
+	// Pick up an IAVL race fix.
+	github.com/cosmos/iavl => github.com/cosmos/iavl v0.19.7
 
 	// Async version negotiation
 	github.com/cosmos/ibc-go/v6 => github.com/agoric-labs/ibc-go/v6 v6.2.1-alpha.agoric.3

golang/cosmos/go.sum

@@ -232,8 +232,8 @@ github.com/aead/siphash v1.0.1/go.mod h1:Nywa3cDsYNNK3gaciGTWPwHt0wlpNV15vwmswBA
 github.com/afex/hystrix-go v0.0.0-20180502004556-fa1af6a1f4f5/go.mod h1:SkGFH1ia65gfNATL8TAiHDNxPzPdmEL5uirI2Uyuz6c=
 github.com/agoric-labs/cometbft v0.34.30-alpha.agoric.1 h1:tqCNL72pQXdUmBzgv1md5SN2U3K/PaYQ4qZ5pFv8v6w=
 github.com/agoric-labs/cometbft v0.34.30-alpha.agoric.1/go.mod h1:myvkihZD8eg9jKE3WFaugkNoL5nvEqlP7Jbjg98pCek=
-github.com/agoric-labs/cosmos-sdk v0.46.16-alpha.agoric.2.1 h1:VZFX9Mogwt4cVTnkdt9zA6UJue4XYXdBURNhlTWw71Q=
-github.com/agoric-labs/cosmos-sdk v0.46.16-alpha.agoric.2.1/go.mod h1:zUe5lsg/X7SeSO1nGkzOh9EGKO295szfrxIxYmeLYic=
+github.com/agoric-labs/cosmos-sdk v0.46.16-alpha.agoric.2.3 h1:EpuIGO5/l8Hwdo6BhRCvETys6HrFvDBbbtarT9L+gKg=
+github.com/agoric-labs/cosmos-sdk v0.46.16-alpha.agoric.2.3/go.mod h1:d7e4h+w7FNBNmE6ysp6duBVuQg67pqMtvsLwpT9ca3E=
 github.com/agoric-labs/cosmos-sdk/ics23/go v0.8.0-alpha.agoric.1 h1:2jvHI/2d+psWAZy6FQ0vXJCHUtfU3ZbbW+pQFL04arQ=
 github.com/agoric-labs/cosmos-sdk/ics23/go v0.8.0-alpha.agoric.1/go.mod h1:E45NqnlpxGnpfTWL/xauN7MRwEE28T4Dd4uraToOaKg=
 github.com/agoric-labs/ibc-go/v6 v6.2.1-alpha.agoric.3 h1:YqvVwK+Lg/ZsuwyVm9UbPs8K55fg00R3Y9KnmaTBdgc=
@@ -378,8 +378,8 @@ github.com/cosmos/go-bip39 v1.0.0 h1:pcomnQdrdH22njcAatO0yWojsUnCO3y2tNoV1cb6hHY
 github.com/cosmos/go-bip39 v1.0.0/go.mod h1:RNJv0H/pOIVgxw6KS7QeX2a0Uo0aKUlfhZ4xuwvCdJw=
 github.com/cosmos/gorocksdb v1.2.0 h1:d0l3jJG8M4hBouIZq0mDUHZ+zjOx044J3nGRskwTb4Y=
 github.com/cosmos/gorocksdb v1.2.0/go.mod h1:aaKvKItm514hKfNJpUJXnnOWeBnk2GL4+Qw9NHizILw=
-github.com/cosmos/iavl v0.19.6 h1:XY78yEeNPrEYyNCKlqr9chrwoeSDJ0bV2VjocTk//OU=
-github.com/cosmos/iavl v0.19.6/go.mod h1:X9PKD3J0iFxdmgNLa7b2LYWdsGd90ToV5cAONApkEPw=
+github.com/cosmos/iavl v0.19.7 h1:ij32FaEnwxfEurtK0QKDNhTWFnz6NUmrI5gky/WnoY0=
+github.com/cosmos/iavl v0.19.7/go.mod h1:X9PKD3J0iFxdmgNLa7b2LYWdsGd90ToV5cAONApkEPw=
 github.com/cosmos/ibc-apps/middleware/packet-forward-middleware/v6 v6.1.2 h1:Hz4nkpStoXIHrC77CIEyu2mRiN2qysGEZPFRf0fpv7w=
 github.com/cosmos/ibc-apps/middleware/packet-forward-middleware/v6 v6.1.2/go.mod h1:Jo934o/sW7fNxuOa/TjCalSalz+1Fd649eLyANaJx8g=
 github.com/cosmos/keyring v1.2.0 h1:8C1lBP9xhImmIabyXW4c3vFjjLiBdGCmfLUfeZlV1Yo=