t: increase timeouts for slow commands with high load

We've seen many fails on ofborg, at lot of them ultimately appear to come down to
a timeout being hit, resulting in something like this:

Failure executing slapadd -F /<path>/slap.d -b dc=example -l /<path>/load.ldif.

Hopefully this resolves it for most cases.
I've done some endurance testing and this helps a lot.
some other commands also regularly time-out with high load:

- hydra-init
- hydra-create-user
- nix-store --delete

This should address most issues with tests randomly failing.

Used the following script for endurance testing:

```

import os
import subprocess

run_counter = 0
fail_counter = 0

while True:
    try:
        run_counter += 1
        print(f"Starting run {run_counter}")
        env = os.environ
        env["YATH_JOB_COUNT"] = "20"
        result = subprocess.run(["perl", "t/test.pl"], env=env)
        if (result.returncode != 0):
            fail_counter += 1
        print(f"Finish run {run_counter}, total fail count: {fail_counter}")
    except KeyboardInterrupt:
        print(f"Finished {run_counter} runs with {fail_counter} fails")
        break
```

In case someone else wants to do it on their system :).
Note that YATH_JOB_COUNT may need to be changed loosely based on your
cores.
I only have 4 cores (8 threads), so for others higher numbers might
yield better results in hashing out unstable tests.

t/lib/HydraTestContext.pm

@@ -92,7 +92,7 @@ sub new {
         $opts{'before_init'}->($self);
     }
 
-    expectOkay(5, ("hydra-init"));
+    expectOkay(30, ("hydra-init"));
 
     return $self;
 }

t/lib/LDAPContext.pm

@@ -70,7 +70,7 @@ sub add_user {
     my $email = $opts{'email'} // "$name\@example";
     my $password = $opts{'password'} // rand_chars();
 
-    my ($res, $stdout, $stderr) = captureStdoutStderr(1, ("slappasswd", "-s", $password));
+    my ($res, $stdout, $stderr) = captureStdoutStderr(5, ("slappasswd", "-s", $password));
     if ($res) {
         die "Failed to execute slappasswd ($res): $stderr, $stdout";
     }
@@ -178,7 +178,7 @@ sub start {
 sub validateConfig {
     my ($self) = @_;
 
-    expectOkay(1, ("slaptest", "-u", "-F", $self->{"_slapd_dir"}));
+    expectOkay(5, ("slaptest", "-u", "-F", $self->{"_slapd_dir"}));
 }
 
 sub _spawn {
@@ -218,7 +218,7 @@ sub load_ldif {
 
     my $path = "${\$self->{'_tmpdir'}}/load.ldif";
     write_file($path, $content);
-    expectOkay(1, ("slapadd", "-F", $self->{"_slapd_dir"}, "-b", $suffix, "-l", $path));
+    expectOkay(5, ("slapadd", "-F", $self->{"_slapd_dir"}, "-b", $suffix, "-l", $path));
     $self->validateConfig();
 }