let Nim support Nimble 0.14 with lock-file support [backport:1.6] (#19236)

(cherry picked from commit 908fc2a22e)

changelog.md

@@ -60,5 +60,9 @@
 - The `gc` switch has been renamed to `mm` ("memory management") in order to reflect the
   reality better. (Nim moved away from all techniques based on "tracing".)
 
+- Nim now supports Nimble version 0.14 which added support for lock-files. This is done by
+  a simple configuration change setting that you can do yourself too. In `$nim/config/nim.cfg`
+  replace `pkgs` by `pkgs2`.
+
 - There is a new switch `--nimMainPrefix:prefix` to influence the `NimMain` that the
   compiler produces. This is particularly useful for generating static libraries.

config/nim.cfg

@@ -44,10 +44,12 @@ path="$lib/core"
 path="$lib/pure"
 
 @if not windows:
+  nimblepath="/opt/nimble/pkgs2/"
   nimblepath="/opt/nimble/pkgs/"
 @else:
   # TODO:
 @end
+nimblepath="$home/.nimble/pkgs2/"
 nimblepath="$home/.nimble/pkgs/"
 
 # Syncronize with compiler/commands.specialDefine