Fix Windows unit-test failure on POSIX-only liveness probe tests

Two liveness-probe deftests had their bodies wrapped in
(when-not h/windows? ...). On Windows the body short-circuited to
nil, leaving the deftest with no (is ...) and causing kaocha to
report "Test ran without assertions" and fail the Windows unit
job. Skip the deftests at the var-definition level instead so they
simply do not exist on Windows.

🤖 Generated with [eca](https://eca.dev)

Co-Authored-By: eca-agent <git@eca.dev>

Author: ericdallo

test/eca/server_test.clj

@@ -28,8 +28,12 @@
                                               #(throw (ex-info "boom" {}))))
         "start! must not raise even when on-exit throws")))
 
-(deftest start-liveness-probe-with-alive-parent-test
-  (when-not h/windows?
+;; The two deftests below are skipped on Windows: they rely on `sleep` and on
+;; POSIX-style subprocess semantics that the liveness probe targets. Skipping
+;; the whole `deftest` (rather than gating only its body) keeps kaocha from
+;; reporting "Test ran without assertions" on Windows.
+(when-not h/windows?
+  (deftest start-liveness-probe-with-alive-parent-test
     (testing "an alive parent does not trigger on-exit"
       (let [proc (spawn-blocking-process)
             exited? (promise)]
@@ -41,8 +45,8 @@
           (finally
             (p/destroy-tree proc)))))))
 
-(deftest start-liveness-probe-fires-when-parent-dies-test
-  (when-not h/windows?
+(when-not h/windows?
+  (deftest start-liveness-probe-fires-when-parent-dies-test
     (testing "killing the parent triggers on-exit"
       (let [proc (spawn-blocking-process)
             exited? (promise)]