Restore outdated local/remote-slsb attributes for declaration compatibility

Legacy EJB attributes are ignored since 6.0 due to being bound to a plain JndiObjectFactoryBean - but can still be declared now, e.g. when validating against the common versions of spring-jee.xsd out there.

Closes gh-31627

spring-context/src/main/resources/org/springframework/ejb/config/spring-jee.xsd

@@ -95,7 +95,7 @@
 		</xsd:complexType>
 	</xsd:element>
 
-	<xsd:element name="local-slsb" type="jndiLocatingType">
+	<xsd:element name="local-slsb" type="ejbType">
 		<xsd:annotation>
 			<xsd:documentation source="java:org.springframework.jndi.JndiObjectFactoryBean"><![CDATA[
 	Exposes a reference to a local EJB Stateless SessionBean.
@@ -103,15 +103,56 @@
 		</xsd:annotation>
 	</xsd:element>
 
-	<xsd:element name="remote-slsb" type="jndiLocatingType">
+	<xsd:element name="remote-slsb">
 		<xsd:annotation>
 			<xsd:documentation source="java:org.springframework.jndi.JndiObjectFactoryBean"><![CDATA[
 	Exposes a reference to a remote EJB Stateless SessionBean.
 			]]></xsd:documentation>
 		</xsd:annotation>
+		<xsd:complexType>
+			<xsd:complexContent>
+				<xsd:extension base="ejbType">
+					<xsd:attribute name="home-interface" type="xsd:string">
+						<xsd:annotation>
+							<xsd:documentation source="java:java.lang.Class"><![CDATA[
+	The home interface that will be narrowed to before performing the
+	parameterless SLSB create() call that returns the actual SLSB proxy.
+	NOTE: Effectively ignored as of 6.0 in favor of plain JNDI lookups.
+							]]></xsd:documentation>
+						</xsd:annotation>
+					</xsd:attribute>
+					<xsd:attribute name="refresh-home-on-connect-failure" type="xsd:boolean" default="false">
+						<xsd:annotation>
+							<xsd:documentation><![CDATA[
+	Controls whether to refresh the EJB home on connect failure.
+	NOTE: Effectively ignored as of 6.0 in favor of plain JNDI lookups.
+
+	Can be turned on to allow for hot restart of the EJB server.
+	If a cached EJB home throws an RMI exception that indicates a
+	remote connect failure, a fresh home will be fetched and the
+	invocation will be retried.
+							]]></xsd:documentation>
+						</xsd:annotation>
+					</xsd:attribute>
+					<xsd:attribute name="cache-session-bean" type="xsd:boolean" default="false">
+						<xsd:annotation>
+							<xsd:documentation><![CDATA[
+	Controls whether to cache the actual session bean object.
+	NOTE: Effectively ignored as of 6.0 in favor of plain JNDI lookups.
+
+	Off by default for standard EJB compliance. Turn this flag
+	on to optimize session bean access for servers that are
+	known to allow for caching the actual session bean object.
+							]]></xsd:documentation>
+						</xsd:annotation>
+					</xsd:attribute>
+				</xsd:extension>
+			</xsd:complexContent>
+		</xsd:complexType>
 	</xsd:element>
 
-	<xsd:complexType name="jndiLocatingType">
+	<!-- base types -->
+	<xsd:complexType name="jndiLocatingType" abstract="true">
 		<xsd:complexContent>
 			<xsd:extension base="beans:identifiedType">
 				<xsd:sequence>
@@ -183,6 +224,40 @@
 		</xsd:complexContent>
 	</xsd:complexType>
 
+	<xsd:complexType name="ejbType">
+		<xsd:complexContent>
+			<xsd:extension base="jndiLocatingType">
+				<xsd:attribute name="lookup-home-on-startup" type="xsd:boolean" default="true">
+					<xsd:annotation>
+						<xsd:documentation><![CDATA[
+	Controls whether the lookup of the EJB home object is performed
+	immediately on startup (if true, the default), or on first access
+	(if false).
+	NOTE: Effectively ignored as of 6.0 in favor of plain JNDI lookups.
+						]]></xsd:documentation>
+					</xsd:annotation>
+				</xsd:attribute>
+				<xsd:attribute name="cache-home" type="xsd:boolean" default="true">
+					<xsd:annotation>
+						<xsd:documentation><![CDATA[
+	Controls whether the EJB home object is cached once it has been located.
+	On by default; turn this flag off to always reobtain fresh home objects.
+	NOTE: Effectively ignored as of 6.0 in favor of plain JNDI lookups.
+						]]></xsd:documentation>
+					</xsd:annotation>
+				</xsd:attribute>
+				<xsd:attribute name="business-interface" type="xsd:string">
+					<xsd:annotation>
+						<xsd:documentation source="java:java.lang.Class"><![CDATA[
+	The business interface of the EJB being proxied.
+	NOTE: Effectively ignored as of 6.0 in favor of plain JNDI lookups.
+						]]></xsd:documentation>
+					</xsd:annotation>
+				</xsd:attribute>
+			</xsd:extension>
+		</xsd:complexContent>
+	</xsd:complexType>
+
 	<xsd:simpleType name="environmentRefType">
 		<xsd:annotation>
 			<xsd:appinfo>