CI: Remove obsolete USE_SLZ=1 CI job

Using SLZ is a default, thus this build is equivalent to the "no features"
build.

diff --git a/.github/matrix.py b/.github/matrix.py
index cfef53c9e14e9280abd528289b0c7da520248f98..fdd76958c692018020144c36b21a01264eb43547 100755 (executable)
--- a/.github/matrix.py
+++ b/.github/matrix.py
@@ -94,7 +94,7 @@ for CC in ["gcc", "clang"]:
         }
     )
 
-    for compression in ["USE_SLZ=1", "USE_ZLIB=1"]:
+    for compression in ["USE_ZLIB=1"]:
         matrix.append(
             {
                 "name": "{}, {}, gz={}".format(