fix: revert oapi to v2.6.0

Author: archandatta

server/Makefile

@@ -24,8 +24,6 @@ oapi-generate: $(OAPI_CODEGEN)
 	$(OAPI_CODEGEN) -config ./oapi-codegen.yaml ./openapi-3.0.yaml
 	@echo "Fixing oapi-codegen issue https://github.com/oapi-codegen/oapi-codegen/issues/1764..."
 	go run ./scripts/oapi/patch_sse_methods -file ./lib/oapi/oapi.go -expected-replacements 3
-	@echo "Patching strict JSON optional bodies (io.EOF) + response omitempty tags..."
-	go run ./scripts/oapi/patch_strict_optional_json -file ./lib/oapi/oapi.go
 	go fmt ./lib/oapi/oapi.go
 	go mod tidy