Consolidate external dependency examples (#18142)

[cj-zhukov]

Which issue does this PR close?

• part of #Reduce the number of distinct binaries to reduce CI / compile time #18142.

Rationale for this change

This PR is for consolidating all the external_dependency examples (dataframe_to_s3, query_aws_s3) into a single example binary. We are agreed on the pattern and we can apply it to the remaining examples

What changes are included in this PR?

Are these changes tested?

Are there any user-facing changes?

[cj-zhukov]

High-Level Overview

This PR consolidates all external_dependency examples (dataframe_to_s3, query_aws_s3) into a single example binary.
Previously, each example had its own file, but now they can be executed via subcommands using:

cargo run --example external_dependency -- [dataframe_to_s3|query_aws_s3]

[cj-zhukov]

It looks like the nyc-tlc bucket is no longer publicly accessible.
Anonymous ListBucket and GetObject requests now return AccessDenied, which makes the example fail even with --no-sign-request:

 aws s3 ls s3://nyc-tlc/  --no-sign-request

I updated the example to use a test Parquet file uploaded to a user-controlled S3 bucket instead.

[2010YOUY01]

It looks like the nyc-tlc bucket is no longer publicly accessible. Anonymous ListBucket and GetObject requests now return AccessDenied, which makes the example fail even with --no-sign-request:

 aws s3 ls s3://nyc-tlc/  --no-sign-request

I updated the example to use a test Parquet file uploaded to a user-controlled S3 bucket instead.

If the CI is currently running this example without errors, the address should be valid — am I missing something? 🤔

[cj-zhukov]

It looks like the nyc-tlc bucket is no longer publicly accessible. Anonymous ListBucket and GetObject requests now return AccessDenied, which makes the example fail even with --no-sign-request:

 aws s3 ls s3://nyc-tlc/  --no-sign-request

I updated the example to use a test Parquet file uploaded to a user-controlled S3 bucket instead.

If the CI is currently running this example without errors, the address should be valid — am I missing something? 🤔

I might be missing something here, but I wasn’t able to access the s3://nyc-tlc bucket from my machine - even

aws s3 ls s3://nyc-tlc/ --no-sign-request 

returns AccessDenied.

One possibility is that CI is running the example with temporary AWS credentials in the environment, so the request becomes signed, which would explain why it still works there.

To confirm whether the bucket is still publicly accessible, could you please try running the same aws s3 ls command on your side?

If it is public, I will revert my change; if not, we can keep the example using a user-controlled bucket to avoid confusion for others.