Workflow invocation export to BioCompute: error when a creator has an email attribute

**Describe the bug**

The workflow invocation export to BioCompute object is failing and raising an error when there is in the workflow a creator with an email attribute. It happens if the email is empty or not and even if the email is valid.

**Galaxy Version and/or server at which you observed the bug**
Galaxy servers: UseGalaxy France, UseGalaxy Europe
Galaxy Version: 23.1, 24.0

**Browser and Operating System**
Operating System: macOS
Browser: Firefox

**To Reproduce**
Steps to reproduce the behavior:
1. Create a workflow that includes a creator with an email attribute

Example of workflow that fails (creator with email attribute): https://usegalaxy.fr/u/bebatut/w/copy-of-test-biocompute-email-issue---sans-email-dans-attributs
Example of workflow that works (creator without email attribute): https://usegalaxy.fr/u/bebatut/w/copy-of-test-biocompute-email-issue---sans-createurs-sauf-abromics

3. Run the workflow (example of input history: https://usegalaxy.fr/u/bebatut/h/test-biocompute-email-issue)

4. Export the workflow invocation to BioCompute object

**Expected behavior**
Error generated

```
err_msg "Unknown error: 1 validation error for Contributor\nemail\n value is not a valid email address: The email address contains invalid characters before the @-sign: ':'. [type=value_error, input_value='mailto:berenice.batut@uca.fr', input_type=str]"
err_code 500001
```