bump changelog to 50.13-r4 #1688

Job	Run time
validate	15s
validate	27s
validate	27s
docs / Build linux64	46s
docs / Build linux64	1m 48s
docs / Build linux64	1m 48s
test / Windows MSVC / Build win64	14s
test / Windows MSVC / Build win64	3m 57s
test / Windows MSVC / Build win64	3m 57s
test / Linux gcc-10 / Build linux64	33s
test / Linux gcc-10 / Build linux64	1m 13s
test / Linux gcc-10 / Build linux64	1m 13s
test / Linux gcc-12 / Build linux64	25s
test / Linux gcc-12 / Build linux64	1m 21s
test / Linux gcc-12 / Build linux64	1m 21s
test / Run Windows test suite	0s
test / Run Windows test suite (empty config)	0s
test / Run Linux test suite	0s
test / Run Linux test suite (gcc-12, all plugins)	0s
test / Run Linux test suite / Test (ubuntu, gcc-10, default plugins, default config)	49s
test / Run Linux test suite / Test (ubuntu, gcc-10, default plugins, default config)	49s
test / Run Linux test suite (gcc-12, all plugins) / Test (ubuntu, gcc-12, all plugins, default config)	10m 47s
test / Run Linux test suite (gcc-12, all plugins) / Test (ubuntu, gcc-12, all plugins, default config)	52s
test / Run Windows test suite (empty config) / Test (windows, msvc, default plugins, empty config)	57s
test / Run Windows test suite (empty config) / Test (windows, msvc, default plugins, empty config)	57s
test / Run Windows test suite / Test (windows, msvc, default plugins, default config)	1m 5s
test / Run Windows test suite / Test (windows, msvc, default plugins, default config)	1m 5s
	37m 6s

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