remove .github/workflows/ci_ssl.yml; instead run via trunner_thirdparty (#16221)

tests/misc/trunner_special.nim

@@ -0,0 +1,31 @@
+discard """
+  targets: "c cpp"
+  joinable: false
+"""
+
+#[
+Runs tests that require special treatment, e.g. because they rely on 3rd party code
+or require external networking.
+
+xxx test all tests/untestable/* here, possibly with adjustments to make running times reasonable
+]#
+
+import std/[strformat,os,unittest,compilesettings]
+import stdtest/specialpaths
+
+const
+  nim = getCurrentCompilerExe()
+  mode = querySetting(backend)
+
+proc runCmd(cmd: string) =
+  let ret = execShellCmd(cmd)
+  check ret == 0 # allows more than 1 failure
+
+proc main =
+  let options = fmt"-b:{mode} --hints:off"
+  block: # SSL nimDisableCertificateValidation integration tests
+    runCmd fmt"{nim} r {options} -d:nimDisableCertificateValidation -d:ssl {testsDir}/untestable/thttpclient_ssl_disabled.nim"
+  block: # SSL certificate check integration tests
+    runCmd fmt"{nim} r {options} -d:ssl --threads:on {testsDir}/untestable/thttpclient_ssl_remotenetwork.nim"
+
+main()