chore: Add shell.nix for all operators

[NickLarsenNZ]

This is based on what I was doing in stackabletech/secret-operator#344, but to extend it out to all operators.

Important

Each operator will need to have Cargo.nix checked in to be able to make use of these changes. Otherwise they will get the following error when running nix-shell:

error: getting status of '.../Cargo.nix': No such file or directory

Run:

make regenerate-nix
git add Cargo.nix crate-hashes.json
git commit -m "add crate2nix generated files"

niv add stackabletech/beku.py
git add nix/source.json
git commit -m "add niv dependencies"

It includes some packages that are only needed for secret-operator:

• They are supposed to already be discovered/provided by default.nix, but I can't get it working.
• If we can't fix the above point, then perhaps we can call out to another nix file that lists additional packages needed by that operator (but then most of then would need to provide a basically empty extra nix file).

---

This will also skip spell-checking in listed generated files.

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I'll go through the PRs this generates so I can add in the missing generated files.

### Products
- [ ] https://github.com/stackabletech/airflow-operator/pull/388
- [ ] https://github.com/stackabletech/druid-operator/pull/519
- [ ] https://github.com/stackabletech/hbase-operator/pull/456
- [ ] https://github.com/stackabletech/hdfs-operator/pull/476
- [ ] https://github.com/stackabletech/hive-operator/pull/417
- [ ] https://github.com/stackabletech/kafka-operator/pull/665
- [ ] https://github.com/stackabletech/nifi-operator/pull/575
- [ ] https://github.com/stackabletech/spark-k8s-operator/pull/360
- [ ] https://github.com/stackabletech/superset-operator/pull/458
- [ ] https://github.com/stackabletech/trino-operator/pull/540
- [ ] https://github.com/stackabletech/zookeeper-operator/pull/773
- [ ] https://github.com/stackabletech/commons-operator/pull/213
- [ ] https://github.com/stackabletech/listener-operator/pull/150
- [ ] https://github.com/stackabletech/opa-operator/pull/527
- [ ] https://github.com/stackabletech/secret-operator/pull/373
- [ ] https://github.com/stackabletech/edc-operator/pull/56
- [ ] https://github.com/stackabletech/hello-world-operator/pull/55

[nightkr]

One minor thing, otherwise LGTM.

[NickLarsenNZ]

@lfrancke, moving this back to In Progress to track the needed changes in each generated PR.