Remove obsolete java api make target.

Makefile

@@ -45,21 +45,6 @@ api:
 	       --openapi_out=fq_schema_naming=true,default_response=false:. \
 	       $(API_PROTO_FILES)
 
-.PHONY: java_api
-# generate java_api proto
-# REQUIRED: protoc-gen-grpc-java plugin from https://repo.maven.apache.org/maven2/io/grpc/protoc-gen-grpc-java/1.63.0/
-# on your path. Then:
-#   chmod u+x <PATH>/protoc-gen-grpc-java-1.63.0-osx-aarch_64.exe
-#   ln -s <PATH>/protoc-gen-grpc-java-1.63.0-<ARCH>.exe protoc-gen-grpc-java
-java_api:
-	mkdir -p ./relations-client-java/src/main/java
-	protoc --proto_path=./api \
-		   --proto_path=./third_party \
-		   --java_out=./relations-client-java/src/main/java \
-		   --plugin=protoc-gen-grpc-java \
-		   --grpc-java_out=./relations-client-java/src/main/java \
-		   $(API_PROTO_FILES)
-
 .PHONY: build
 # build
 build: