replace equalto and occursin with curried isequal, ==, and `i…

…n` (#26436)

test/distributed_exec.jl

@@ -1036,7 +1036,7 @@ if DoFullTest
     pids=addprocs_with_testenv(4);
     @test_throws ErrorException rmprocs(pids; waitfor=0.001);
     # wait for workers to be removed
-    while any(occursin(procs()), pids)
+    while any(in(procs()), pids)
         sleep(0.1)
     end
 end
@@ -1483,7 +1483,7 @@ function reuseport_tests()
     end
 
     # Ensure that the code has indeed been successfully executed everywhere
-    @test all(occursin(results), procs())
+    @test all(in(results), procs())
 end
 
 # Test that the client port is reused. SO_REUSEPORT may not be supported on