Simplify command invocation

(cherry picked from commit 732a959d9a)

bin/tests/system/isctest/kasp.py

@@ -291,8 +291,7 @@ def check_dnssec_verify(server, zone):
                 file.write(rr.to_text())
                 file.write("\n")
 
-    verify_command = [*os.environ.get("VERIFY").split(), "-z", "-o", zone, zonefile]
-
+    verify_command = [os.environ.get("VERIFY"), "-z", "-o", zone, zonefile]
     isctest.run.cmd(verify_command)
 
 

bin/tests/system/ksr/tests_ksr.py

@@ -49,7 +49,7 @@ def keystr_to_keylist(keystr: str, keydir: Optional[str] = None) -> List[Key]:
 
 def keygen(zone, policy, keydir, when="now"):
     keygen_command = [
-        *os.environ.get("KEYGEN").split(),
+        os.environ.get("KEYGEN"),
         "-l",
         "ns1/named.conf",
         "-fK",
@@ -71,7 +71,7 @@ def keygen(zone, policy, keydir, when="now"):
 
 def ksr(zone, policy, action, options="", raise_on_exception=True):
     ksr_command = [
-        *os.environ.get("KSR").split(),
+        os.environ.get("KSR"),
         "-l",
         "ns1/named.conf",
         "-k",