chore: Bump nimbus and nim to latest available - nim-2.0.12

[NagyZoltanPeter]

Description

To unstuck waku-sync v2 we need to move to latest nim version.
Currently it is 2.0.12

Changes

• nimbus-build-system is bumped to latest master that includes nim v2.0.12

Note:

Currently, this new nim version breaks our code. We need to investigate if it is possible to adjust nim flags for backward compatible build or we can easily adjust our code.

Example error appears with latest nim version:

/home/nzp/dev/status/nwaku/waku/waku_api/rest/debug/types.nim(50, 31) template/generic instantiation of `unrecognizedFieldWarning` from here
/home/nzp/dev/status/nwaku/vendor/nim-chronicles/chronicles.nim(380, 10) template/generic instantiation of `log` from here
/home/nzp/dev/status/nwaku/waku/waku_api/rest/serdes.nim(28, 50) Warning: a new symbol 'value' has been injected during template or generic instantiation, however overloads of value will be used instead; either enable --experimental:openSym to use the injected symbol, or `bind` this symbol explicitly [IgnoredSymbolInjection]
/home/nzp/dev/status/nwaku/waku/waku_api/rest/debug/types.nim(50, 31) template/generic instantiation of `unrecognizedFieldWarning` from here
/home/nzp/dev/status/nwaku/vendor/nim-chronicles/chronicles.nim(380, 10) template/generic instantiation of `log` from here
/home/nzp/dev/status/nwaku/waku/waku_api/rest/serdes.nim(28, 50) Error: ambiguous identifier: 'value' -- use one of the following:
  results.value: proc (self: var Result[value.T, value.E]): var T: not void{.inline, noSideEffect.}
  results.value: proc (self: Result[system.void, value.E]){.inline, noSideEffect.}
  results.value: proc (self: Result[value.T, value.E]): lent T: not void{.inline, noSideEffect.}