Disable backtrace and PBTs on s390x too (OCaml5 bytecode arch)

Author: jmid

test/dune

@@ -98,7 +98,7 @@
  (name backtrace)
  (libraries domainslib)
  (modules backtrace)
- (enabled_if (and (= %{arch_sixtyfour} true) (<> %{architecture} power))))
+ (enabled_if (and (= %{arch_sixtyfour} true) (<> %{architecture} power) (<> %{architecture} s390x))))
  ;; disabled temporarily on bytecode switches https://github.com/ocaml/dune/issues/7845
 
 (test
@@ -112,14 +112,16 @@
  (name task_one_dep)
  (modules task_one_dep)
  (libraries qcheck-multicoretests-util qcheck-core qcheck-core.runner domainslib)
- (enabled_if (and (= %{arch_sixtyfour} true) (<> %{architecture} power))) ;; takes forever on bytecode
+ (enabled_if (and (= %{arch_sixtyfour} true) (<> %{architecture} power) (<> %{architecture} s390x)))
+ ;; takes forever on bytecode
  (action (run %{test} --verbose)))
 
 (test
  (name task_more_deps)
  (modules task_more_deps)
  (libraries qcheck-multicoretests-util qcheck-core qcheck-core.runner domainslib)
- (enabled_if (and (= %{arch_sixtyfour} true) (<> %{architecture} power))) ;; takes forever on bytecode
+ (enabled_if (and (= %{arch_sixtyfour} true) (<> %{architecture} power) (<> %{architecture} s390x)))
+ ;; takes forever on bytecode
  (action (run %{test} --verbose)))
 
 (test