ci: pin flate2 for msrv

Author: LagginTimes

ci/pin-msrv.sh

@@ -22,3 +22,4 @@ cargo update -p security-framework-sys --precise "2.11.1"
 cargo update -p csv --precise "1.3.0"
 cargo update -p unicode-width --precise "0.1.13"
 cargo update -p native-tls --precise "0.2.13"
+cargo update -p flate2 --precise "1.0.35"