Add changelog for 56.1

CHANGELOG.rst:
Add a changelog entry for 56.1
11 jobs for changelog/56.1 in 79 minutes and 7 seconds (queued for 7 seconds)
Status Name Job ID Coverage
  Check
passed check #28855

00:00:22

 
  Build
passed build_long: [baseline iso] #28858
fast-single-thread

00:31:34

passed build_long: [baseline netboot] #28871
fast-single-thread

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passed build_long: [releng iso] #28869
fast-single-thread

00:46:29

passed build_long: [releng netboot] #28870
fast-single-thread

00:46:55

passed build_short: [baseline bootstrap] #28856

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passed build_short: [releng bootstrap] #28857

00:20:21

canceled build_long: [baseline netboot] #28868
fast-single-thread

00:00:01

failed build_long: [baseline netboot] #28859
fast-single-thread

00:57:08

failed build_long: [releng iso] #28860
fast-single-thread

01:00:01

failed build_long: [releng netboot] #28861
fast-single-thread

01:00:01