test: Close modal in TestSystemInfo.testCryptoPolicies

Close the crypto policy dialog after checking the default value. Leaving
it open and clicking around on the main page is cheating and prone to
race conditions, and will fail with the next commit.

test/verify/check-system-info

@@ -799,6 +799,8 @@ password=foobar
         b.click("#crypto-policy-button")
         func = b.wait_not_present if m.image.startswith('rhel-8') or m.image.startswith('centos-8') else b.wait_visible
         func(".pf-v5-c-menu__item-main .pf-v5-c-menu__item-text:contains('DEFAULT:SHA1')")
+        b.click("#crypto-policy-dialog button:contains('Cancel')")
+        b.wait_not_present("#crypto-policy-dialog")
 
         # Test if a new subpolicy can be set
         new_profile = "LEGACY:AD-SUPPORT"