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

tests/misc/trunner.nim

@@ -7,7 +7,7 @@ discard """
 ## A few others could be added to here to simplify code.
 ## Note: this test is a bit slow but tests a lot of things; please don't disable.
 
-import std/[strformat,os,osproc,unittest]
+import std/[strformat,os,osproc,unittest,compilesettings]
 from std/sequtils import toSeq,mapIt
 from std/algorithm import sorted
 import stdtest/[specialpaths, unittest_light]
@@ -25,10 +25,7 @@ const
     # useful when you want to turn only some hints on, and some common ones off.
     # pending https://github.com/timotheecour/Nim/issues/453, simplify to: `--hints:off`
   nim = getCurrentCompilerExe()
-  mode =
-    when defined(c): "c"
-    elif defined(cpp): "cpp"
-    else: static: doAssert false
+  mode = querySetting(backend)
   nimcache = buildDir / "nimcacheTrunner"
     # instead of `querySetting(nimcacheDir)`, avoids stomping on other parallel tests
 

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()