Fix typo in error message for collection existence (#5080)

Signed-off-by: HartLi <[email protected]>
(cherry picked from commit a3a5f54)

Author: Hart-Li

vector-stores/spring-ai-chroma-store/src/main/java/org/springframework/ai/chroma/vectorstore/ChromaApi.java

@@ -228,7 +228,7 @@ public Collection getCollection(String tenantName, String databaseName, String c
 		}
 		catch (HttpServerErrorException | HttpClientErrorException e) {
 			String msg = this.getErrorMessage(e);
-			if (String.format("Collection [%s] does not exists", collectionName).equals(msg)) {
+			if (String.format("Collection [%s] does not exist", collectionName).equals(msg)) {
 				return null;
 			}
 			throw new RuntimeException(msg, e);