fix(deps): update dependency webpack-merge to v6 #32094

Job	Run time
collect-and-verify	4m 26s
lms-1(py=3.11,dj=pinned,mongo=7.0)	11m 17s
lms-2(py=3.11,dj=pinned,mongo=7.0)	11m 42s
lms-3(py=3.11,dj=pinned,mongo=7.0)	15m 32s
lms-4(py=3.11,dj=pinned,mongo=7.0)	19m 44s
lms-5(py=3.11,dj=pinned,mongo=7.0)	11m 5s
lms-6(py=3.11,dj=pinned,mongo=7.0)	15m 40s
openedx-1-with-lms(py=3.11,dj=pinned,mongo=7.0)	11m 48s
openedx-2-with-lms(py=3.11,dj=pinned,mongo=7.0)	17m 4s
openedx-1-with-cms(py=3.11,dj=pinned,mongo=7.0)	8m 24s
openedx-2-with-cms(py=3.11,dj=pinned,mongo=7.0)	6m 16s
cms-1(py=3.11,dj=pinned,mongo=7.0)	4m 50s
cms-2(py=3.11,dj=pinned,mongo=7.0)	12m 43s
common-with-lms(py=3.11,dj=pinned,mongo=7.0)	9m 59s
common-with-cms(py=3.11,dj=pinned,mongo=7.0)	6m 24s
xmodule-with-lms(py=3.11,dj=pinned,mongo=7.0)	8m 32s
xmodule-with-cms(py=3.11,dj=pinned,mongo=7.0)	9m 6s
xmodule-with-cms(py=3.11,dj=pinned,mongo=7.0)	8m 24s
xmodule-with-lms(py=3.11,dj=pinned,mongo=7.0)	8m 32s
Unit tests successful	4s
coverage (3.11)	1m 43s
compile-warnings-report	13s
merge-artifacts	7s
	3h 23m 35s

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