Remove links to Spring Data GemFire

Closes gh-42575

Author: mhalbritter

spring-boot-project/spring-boot-docs/src/docs/asciidoc/attributes.adoc

@@ -66,7 +66,6 @@
 :spring-data-elasticsearch: https://spring.io/projects/spring-data-elasticsearch
 :spring-data-elasticsearch-docs: https://docs.spring.io/spring-data/elasticsearch/reference/{spring-data-elasticsearch-version-antora}
 :spring-data-envers: https://spring.io/projects/spring-data-envers
-:spring-data-gemfire: https://spring.io/projects/spring-data-gemfire
 :spring-data-geode: https://spring.io/projects/spring-data-geode
 :spring-data-jdbc-docs: https://docs.spring.io/spring-data/relational/reference/{spring-data-jdbc-version-antora}
 :spring-data-jpa: https://spring.io/projects/spring-data-jpa

spring-boot-project/spring-boot-docs/src/docs/asciidoc/data/nosql.adoc

@@ -5,7 +5,7 @@ Spring Data provides additional projects that help you access a variety of NoSQL
 * {spring-data-cassandra}[Cassandra]
 * {spring-data-couchbase}[Couchbase]
 * {spring-data-elasticsearch}[Elasticsearch]
-* {spring-data-gemfire}[GemFire] or {spring-data-geode}[Geode]
+* {spring-data-geode}[Geode]
 * {spring-data-ldap}[LDAP]
 * {spring-data-mongodb}[MongoDB]
 * {spring-data-neo4j}[Neo4J]