Don't invoke beforeSend for transactions

[philipphofmann]

Description

The SDK must not invoke beforeSend for transactions. If users want to drop transactions, they should instead use event processors, see https://develop.sentry.dev/sdk/performance/#interaction-with-beforesend-and-event-processors or beforeSendTransaction see #3339.

As some users might rely on calling beforeSend to drop transactions and event processors are not public, this change is a breaking change. Please remember that some users could also use beforeSend to send transactions to another endpoint, so we have to provide an alternative.

[ndmanvar]

@philipphofmann please let me know if we fix this

[philipphofmann]

@ndmanvar, we can only fix this with a major version as pointed out above

As some users might rely on calling beforeSend to drop transactions and event processors are not public, this change is a breaking change. Please remember that some users could also use beforeSend to send transactions to another endpoint, so we have to provide an alternative.

So when we are going to fix this, we make sure to not break anybody.

[github-actions]

This issue has gone three weeks without activity. In another week, I will close it.

But! If you comment or otherwise update it, I will reset the clock, and if you label it Status: Backlog or Status: In Progress, I will leave it alone ... forever!

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"A weed is but an unloved flower." ― Ella Wheeler Wilcox 🥀