Remove the uses of {.procvar.} pragma (#14359)

This pragma did nothing.

Ref:
- https://github.com/nim-lang/Nim/issues/2172#issuecomment-383276469
- https://github.com/nim-lang/Nim/issues/12975

tests/manyloc/argument_parser/argument_parser.nim

@@ -102,7 +102,7 @@ type
 
 # - Tparam_kind procs
 
-proc `$`*(value: Tparam_kind): string {.procvar.} =
+proc `$`*(value: Tparam_kind): string =
   ## Stringifies the type, used to generate help texts.
   case value:
   of PK_EMPTY: result = ""
@@ -137,7 +137,7 @@ proc new_parameter_specification*(consumes = PK_EMPTY,
 
 # - Tparsed_parameter procs
 
-proc `$`*(data: Tparsed_parameter): string {.procvar.} =
+proc `$`*(data: Tparsed_parameter): string =
   ## Stringifies the value, mostly for debug purposes.
   ##
   ## The proc will display the value followed by non string type in brackets.

tests/manyloc/keineschweine/lib/client_helpers.nim

@@ -69,7 +69,7 @@ proc updateFileProgress*() =
   downloadProgress.setString($currentFileTransfer.pos & '/' & $currentFileTransfer.fullLen)
 
 ## HFileTransfer
-proc handleFilePartRecv*(serv: PServer; buffer: PBuffer) {.procvar.} =
+proc handleFilePartRecv*(serv: PServer; buffer: PBuffer) =
   var
     f = readScFileTransfer(buffer)
   updateFileProgress()
@@ -110,7 +110,7 @@ proc saveCurrentFile() =
   echo "Write file"
 
 ## HChallengeResult
-proc handleFileChallengeResult*(serv: PServer; buffer: PBuffer) {.procvar.} =
+proc handleFileChallengeResult*(serv: PServer; buffer: PBuffer) =
   var res = readScChallengeResult(buffer).status
   echo "got challnege result: ", res
   if res and currentFileTransfer.readyToSave:
@@ -122,7 +122,7 @@ proc handleFileChallengeResult*(serv: PServer; buffer: PBuffer) {.procvar.} =
     echo "REsetting current file"
 
 ## HFileCHallenge
-proc handleFileChallenge*(serv: PServer; buffer: PBuffer) {.procvar.} =
+proc handleFileChallenge*(serv: PServer; buffer: PBuffer) =
   var
     challenge = readScFileChallenge(buffer)
     path = expandPath(challenge)