Add a recomended extras group (#313)

## Summary

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the changes are necessary.
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Adds a python extras group for recommended packages and adds a couple
optional tokenizer packages to it.

## Details

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- Adds the `recommended` package group with `tiktoken`, and `blobfile`
- ~Add `default-optional-dependency-keys` field for future compatibly
with PEP 771 compliant tools~ pip is picky about the key in `[project]`
so reverted. Since the group name is the default I'm not sure this is
even necessary.

---

- [x] "I certify that all code in this PR is my own, except as noted
below."

## Use of AI

- [ ] Includes AI-assisted code completion
- [ ] Includes code generated by an AI application
- [ ] Includes AI-generated tests (NOTE: AI written tests should have a
docstring that includes `## WRITTEN BY AI ##`)

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Signed-off-by: Samuel Monson <[email protected]>

Author: sjmonson

pdm.toml

@@ -1,2 +1,4 @@
+[strategy]
+update = "reuse"
 [lock]
 format = "pylock"