Use much faster gzip compression.

Potentially fixes #193.

Signed-off-by: Tim 'mithro' Ansell <tansell@google.com>

.github/capture.sh

diff --git a/.github/capture.sh b/.github/capture.sh
index 601fdb9..ca0bce1 100644
--- a/.github/capture.sh
+++ b/.github/capture.sh
@@ -40,7 +40,7 @@
 	cd ${SKY130_DIR}
 	tar \
 		--create \
-		--xz \
+		--gzip \
 		--verbose \
 		\
 		--mtime='2020-05-07 00:00Z' \
@@ -50,7 +50,7 @@
 		--numeric-owner \
 		--pax-option=exthdr.name=%d/PaxHeaders/%f,delete=atime,delete=ctime \
 		\
-		--file ${GITHUB_WORKSPACE}/output/pdk-SKY130A-${STD_CELL_LIBRARY}.tar.xz .
+		--file ${GITHUB_WORKSPACE}/output/pdk-SKY130A-${STD_CELL_LIBRARY}.tar.gz .
 
 	echo ::endgroup::
 )