Fix auto random user scenario

[alastori]

What is changed, added or deleted? (Required)

This PR updates the "Clear the auto-increment ID cache" section in auto-random.md to address confusion reported in issue #20732. Specifically, the changes:

• Clarify that ALTER TABLE ... AUTO_RANDOM_BASE without the FORCE keyword does not actually change the value, despite the warning message.
• Emphasize that the FORCE keyword is mandatory to modify AUTO_RANDOM_BASE.
• Explicitly state that attempting to set AUTO_RANDOM_BASE to 0, even with FORCE, will result in an error.
• Clarify that a non-zero positive integer must be used with FORCE.
• Improve the explanation of how explicit inserts can potentially collide with the internal auto-incrementing part of AUTO_RANDOM IDs, potentially leading to duplicate key errors.
• Split a longer paragraph into smaller ones for better readability.

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What is the related PR or file link(s)?

• Closes need to clarify the example in AUTO_RANDOM #20732
• File modified: auto-random.md

Do your changes match any of the following descriptions?

• Delete files
• Change aliases
• Need modification after applied to another branch
• Might cause conflicts after applie

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[alastori]

@Frank945946

[alastori]

Added other commits by mistake. I will close/cancel this PR and submit another.