fix(simapp): concurrent map writes when calling GetSigners (backport #21073) (#21126)

Co-authored-by: Facundo Medica <14063057+facundomedica@users.noreply.github.com>
Co-authored-by: Facundo <facundomedica@gmail.com>
Co-authored-by: Julien Robert <julien@rbrt.fr>

Author: 3 people

simapp/app.go

@@ -213,6 +213,10 @@ func NewSimApp(
 	signingCtx := interfaceRegistry.SigningContext()
 	txConfig := authtx.NewTxConfig(appCodec, signingCtx.AddressCodec(), signingCtx.ValidatorAddressCodec(), authtx.DefaultSignModes)
 
+	if err := signingCtx.Validate(); err != nil {
+		panic(err)
+	}
+
 	std.RegisterLegacyAminoCodec(legacyAmino)
 	std.RegisterInterfaces(interfaceRegistry)