Some tutorials mention Haystack 2.0 but use Haystack >=2.3

[julian-risch]

"This tutorial uses Haystack 2.0" or "Install Haystack 2.0 with pip:" is mentioned in some tutorials although we install the most recent release, which is 2.3.1 or soon 2.4.0. We should remove the mention of the explicit version. Other tutorials use "To start, let's install the latest release of Haystack with pip:" for example.

• https://github.com/deepset-ai/haystack-tutorials/blob/13a85a851adde687b713fa085ecf9db18318fc79/tutorials/29_Serializing_Pipelines.ipynb
• https://github.com/deepset-ai/haystack-tutorials/blob/13a85a851adde687b713fa085ecf9db18318fc79/tutorials/37_Simplifying_Pipeline_Inputs_with_Multiplexer.ipynb
• https://github.com/deepset-ai/haystack-tutorials/blob/13a85a851adde687b713fa085ecf9db18318fc79/tutorials/39_Embedding_Metadata_for_Improved_Retrieval.ipynb
• https://github.com/deepset-ai/haystack-tutorials/blob/13a85a851adde687b713fa085ecf9db18318fc79/tutorials/36_Building_Fallbacks_with_Conditional_Routing.ipynb
• https://github.com/deepset-ai/haystack-tutorials/blob/13a85a851adde687b713fa085ecf9db18318fc79/tutorials/33_Hybrid_Retrieval.ipynb
• ... there are more
• https://github.com/deepset-ai/haystack-tutorials/blob/13a85a851adde687b713fa085ecf9db18318fc79/tutorials/28_Structured_Output_With_Loop.ipynb (I have a PR open for this one here chore: Install Haystack stable release instead of main branch #342)