Reverts noshebang test fixes

The hope is that the noshebang test was fixed on old glibc
through e74b9d53df. Revert the previous optimistic attempts to
fix these through adding sleeps and subshells.

This reverts commit b3da0bd5a2.
This reverts commit 8a86d3452f.

tests/checks/noshebang.fish

@@ -1,11 +1,11 @@
-# RUN: %fish -C'set -g fish (builtin realpath %fish)' %s
+# RUN: %fish %s
 
 # Test for shebangless scripts - see 7802.
 
 set testdir (mktemp -d)
 cd $testdir
 
-$fish -c 'true > file'
+touch file
 chmod a+x file
 
 function runfile
@@ -23,24 +23,22 @@ function runfile
 end
 
 # Empty executable files are 'true'.
-sleep 0.2
+true >file
+sleep 0.1
 runfile
 #CHECK: 0
 #CHECK: 0
 
 # Files without NUL are 'true' as well.
-# NOTE: We redirect in a new process because the file must be *closed*
-# before it can be run. On some systems that doesn't happen quickly enough.
-$fish -c "echo -e -n '#COMMENT\n#COMMENT' >file"
-sleep 0.2
+echo -e -n '#COMMENT\n#COMMENT' >file
 runfile
 #CHECK: 0
 #CHECK: 0
 
 # Never implicitly pass files ending with .fish to /bin/sh.
-touch file.fish
+true >file.fish
+sleep 0.1
 chmod a+x file.fish
-sleep 0.3
 set -g fish_use_posix_spawn 0
 ./file.fish
 echo $status
@@ -61,15 +59,15 @@ rm file.fish
 
 # On to NUL bytes.
 # The heuristic is that there must be a line containing a lowercase letter before the first NUL byte.
-$fish -c "echo -n -e 'true\n\x00' >file"
-sleep 0.3
+echo -n -e 'true\n\x00' >file
+sleep 0.1
 runfile
 #CHECK: 0
 #CHECK: 0
 
 # Doesn't meet our heuristic as there is no newline.
-$fish -c "echo -n -e 'true\x00' >file"
-sleep 0.3
+echo -n -e 'true\x00' >file
+sleep 0.1
 runfile
 #CHECK: 126
 #CHECKERR: Failed {{.*}}
@@ -82,7 +80,7 @@ runfile
 #CHECKERR: {{.*}}
 
 # Doesn't meet our heuristic as there is no lowercase before newline.
-$fish -c "echo -n -e 'NOPE\n\x00' >file"
+echo -n -e 'NOPE\n\x00' >file
 sleep 0.1
 runfile
 #CHECK: 126