[SPARK-45698][CORE][SQL][SS] Clean up the deprecated API usage related to Buffer

[LuciferYang]

What changes were proposed in this pull request?

This PR cleans up the use of the following APIs in s.c.mutable.Buffer, as they have been deprecated after Scala 2.13.0 or Scala 2.13.4:

• trimStart -> dropInPlace
• trimEnd -> dropRightInPlace
• append(elems: A*) -> appendAll
• prepend(elems: A*) -> prependAll(elems)

  @deprecated("use dropInPlace instead", since = "2.13.4")
  def trimStart(n: Int): Unit = dropInPlace(n)

  @deprecated("use dropRightInPlace instead", since = "2.13.4")
  def trimEnd(n: Int): Unit = dropRightInPlace(n)

  @deprecated("Use appendAll instead", "2.13.0")
  @`inline` final def append(elems: A*): this.type = addAll(elems)

  @deprecated("Use prependAll instead", "2.13.0")
  @`inline` final def prepend(elems: A*): this.type = prependAll(elems)

Why are the changes needed?

Clean up deprecated API usage.

Does this PR introduce any user-facing change?

No

How was this patch tested?

Pass GitHub Acitons.

Was this patch authored or co-authored using generative AI tooling?

No

[MaxGekk]

+1, LGTM. Merging to master.
Thank you, @LuciferYang and @HyukjinKwon for review.

[LuciferYang]

Thanks @MaxGekk @HyukjinKwon

[beliefer]

LGTM later.