patch 9.1.1089: tests: No check when tests are run under Github actions

Problem:  tests: No check when tests are run under Github actions
Solution: Add the CheckGithubActions check command and skip test if
          needed

related: #16599
related: actions/runner-images#11512

Signed-off-by: Christian Brabandt <cb@256bit.org>

src/testdir/check.vim

@@ -291,4 +291,11 @@ func CheckAllOf(...)
   endfor
 endfunc
 
+" Check if running under Github Actions
+command CheckGithubActions call CheckGithubActions()
+func CheckGithubActions()
+  if expand('$GITHUB_ACTIONS') ==# 'true'
+    throw "Skipped: FIXME: this test doesn't work on Github Actions CI"
+  endif
+endfunc
 " vim: shiftwidth=2 sts=2 expandtab

src/version.c

@@ -704,6 +704,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1089,
 /**/
     1088,
 /**/