'J' when joining two comment lines does not strip the leading comment indicator

Describe the bug
When executing J in normal mode to join lines, vim strips leading comment indicators if we are joining a comment line to another comment line.

To Reproduce
Steps to reproduce the behavior:

Execute normal J on any of the following lines in a TOML file. The # should be stripped when joining.

# XXX: load-bearing unused dependency.
#
# `rustyline` improperly declares its minimum version on `log` as `0.4` despite
# requiring `>=0.4.5` to compile. Link in at least the minimum version here so
# cargo pulls in at least 0.4.5, e.g. when using `-Zminimal-versions`.
#
# Upstream has not been willing to merge a patch to fix this, so hack around it
# here.
#
# See: https://github.com/kkawakam/rustyline/pull/583

Expected behavior
A clear and concise description of what you expected to happen.

Screenshots
If applicable, add screenshots to help explain your problem.
If remapping-related, please attach log output: https://github.com/VSCodeVim/Vim#debugging-remappings.

neovim behavior:

https://github.com/user-attachments/assets/8d0caec7-ff9a-418e-a5b0-0b7a95008cac

VSCodeVim behavior:

https://github.com/user-attachments/assets/fbc0bce5-9eb0-4539-94a1-800587cf6931

Environment (please complete the following information):

• Extension (VsCodeVim) version: 1.29.0
• VSCode version: 1.96.2
• OS: macOS Sequoia 15.2

Additional context
Add any other context about the problem here.

Start by reproducing normal-mode J on the provided TOML comment block and compare the expected joined text with the current behavior. Trace the normal-mode join entry point and identify the existing coverage for comment joining, then add a regression check ensuring the leading # is removed when two comment lines are joined.