Remove Beta labeling for Code Suggestions settings

Problem

The code suggestions toggle all say Beta

MRs

• .COM Resolve "Remove Beta labeling for SaaS Code Sug... (!139847 - merged)
• Self managed Remove beta label from SM Code Suggestions inst... (!139965 - merged)
• Additional MR: !140072 (merged) may be a duplicated of !139965 (merged)

Proposal

As Code Suggestions (SaaS) is going GA for SaaS on Dec 18, we should remove the beta label in the namespace toggle.

Note: The user preferences code suggestions toggle is being removed - see https://gitlab.com/gitlab-org/gitlab/-/issues/435269

Because above is rolled out incrementally, we should also remove the beta label from personal preferences