htmlzip format consumes too much memory

https://github.com/readthedocs/readthedocs.org/issues/6737

Issue-ID: CIMAN-33
Signed-off-by: Aric Gardner <agardner@linuxfoundation.org>
Change-Id: I0eade3a833ace01bb9a17992e3f246636664054c
diff --git a/.readthedocs.yaml b/.readthedocs.yaml
index f35ca04..10453a9 100644
--- a/.readthedocs.yaml
+++ b/.readthedocs.yaml
@@ -6,9 +6,6 @@
 #
 version: 2
 
-formats:
-   - htmlzip
-
 build:
    image: latest