patch 8.2.2876: configure cannot detect Python 3.10

Problem:    Configure cannot detect Python 3.10.
Solution:   Use sys.version_info. (closes vim#8233)

patch 8.2.2875: cancelling inputlist() after a digit does not return …

…zero

Problem:    Cancelling inputlist() after a digit does not return zero.
Solution:   Always return zero when cancelling. (closes vim#8231)

patch 8.2.2874: MS-Windows: screen redraws too often

Problem:    MS-Windows: screen redraws too often.
Solution:   Do not redraw when peeking for a character. (closes vim#8230,
            closes vim#8211)

patch 8.2.2873: not enough tests for writing buffers

Problem:    Not enough tests for writing buffers.
Solution:   Add a few more tests. (Yegappan Lakshmanan, closes vim#8229)

patch 8.2.2872: Python tests fail without the channel feature

Problem:    Python tests fail without the channel feature.
Solution:   Add a feature check. (Dominique Pellé, closes vim#8226)

patch 8.2.2871: unnessary VIM_ISDIGIT() calls, badly indented code

Problem:    Unnessary VIM_ISDIGIT() calls, badly indented code.
Solution:   Call skipdigits() on the next character.  Improve indenting.
            (Dominique Pellé, closes vim#8227)

patch 8.2.2870: CmdlineChange event triggered twice for CTRL-R

Problem:    CmdlineChange event triggered twice for CTRL-R.
Solution:   Return CMDLINE_NOT_CHANGED from cmdline_insert_reg().
            (closes vim#8219)

patch 8.2.2869: using unified diff is not tested

Problem:    Using unified diff is not tested.
Solution:   Test all cases also with unified diff. (issue vim#8197)

patch 8.2.2868: Vim9: when executing compiled expression trylevel is …

…changed

Problem:    Vim9: When executing a compiled expression the trylevel at start
            is changed but not restored. (closes vim#8214)
Solution:   Restore the trylevel at start.

patch 8.2.2867: build failure

Problem:    Build failure.
Solution:   Add missing part of the change.