Add meta-llama/Llama-3.2-1B tokenizer.json fixture

Pinned copy of meta-llama/Llama-3.2-1B tokenizer.json, for huggingface/tokenizers tk-convert oracle test (byte-level BPE model, gated on the Hub so mirrored here ungated).

fixtures/models/llama-3.2-1b.json

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:79e3e522635f3171300913bb421464a87de6222182a0570b9b2ccba2a964b2b4
+size 9085657