add -d:nimStrictMode in CI to keep code from regressing; fixes ConvFromXtoItselfNotNeeded, UnusedImport notes (#16764)

lib/pure/asyncdispatch.nim

@@ -1279,7 +1279,7 @@ else:
     var newList = newSeqOfCap[Callback](newLength)
 
     var cb = curList[0]
-    if not cb(fd.AsyncFD):
+    if not cb(fd):
       newList.add(cb)
 
     withData(p.selector, fd.int, adata) do:

lib/pure/asyncfutures.nim

@@ -364,7 +364,10 @@ proc read*[T](future: Future[T] | FutureVar[T]): T =
   ##
   ## If the result of the future is an error then that error will be raised.
   {.push hint[ConvFromXtoItselfNotNeeded]: off.}
-  let fut = Future[T](future)
+  when future is Future[T]:
+    let fut = future
+  else:
+    let fut = Future[T](future)
   {.pop.}
   if fut.finished:
     if fut.error != nil:

lib/pure/browsers.nim

@@ -20,7 +20,9 @@ when defined(windows):
   import winlean
   from os import absolutePath
 else:
-  import os, osproc
+  import os
+  when not defined(osx):
+    import osproc
 
 const osOpenCmd* =
   when defined(macos) or defined(macosx) or defined(windows): "open" else: "xdg-open" ## \

lib/pure/concurrency/cpuinfo.nim

@@ -15,7 +15,7 @@ runnableExamples:
 
 include "system/inclrtl"
 
-when not defined(windows):
+when defined(linux):
   import posix
 
 when defined(freebsd) or defined(macosx):

lib/pure/net.nim

@@ -88,7 +88,6 @@
 import std/private/since
 
 import nativesockets, os, strutils, times, sets, options, std/monotimes
-from ssl_certs import scanSSLCertificates
 import ssl_config
 export nativesockets.Port, nativesockets.`$`, nativesockets.`==`
 export Domain, SockType, Protocol
@@ -101,6 +100,8 @@ when useWinVersion:
 
 when defineSsl:
   import openssl
+  when not defined(nimDisableCertificateValidation):
+    from ssl_certs import scanSSLCertificates
 
 # Note: The enumerations are mapped to Window's constants.
 
@@ -670,7 +671,7 @@ when defineSsl:
     # That means we can assume that the next internal index is the length of
     # extra data indexes.
     for i in ctx.referencedData:
-      GC_unref(getExtraData(ctx, i).RootRef)
+      GC_unref(getExtraData(ctx, i))
     ctx.context.SSL_CTX_free()
 
   proc `pskIdentityHint=`*(ctx: SslContext, hint: string) =

lib/pure/osproc.nim

@@ -1234,7 +1234,7 @@ elif not defined(useNimRtl):
 
   when defined(macosx) or defined(freebsd) or defined(netbsd) or
        defined(openbsd) or defined(dragonfly):
-    import kqueue, times
+    import kqueue
 
     proc waitForExit(p: Process, timeout: int = -1): int =
       if p.exitFlag:

lib/pure/terminal.nim

@@ -769,8 +769,6 @@ proc getch*(): char =
     discard fd.tcSetAttr(TCSADRAIN, addr oldMode)
 
 when defined(windows):
-  from unicode import toUTF8, Rune, runeLenAt
-
   proc readPasswordFromStdin*(prompt: string, password: var string):
                               bool {.tags: [ReadIOEffect, WriteIOEffect].} =
     ## Reads a `password` from stdin without printing it. `password` must not