Proposition 6
Tag 00EK, permanent. Cite it as [Bourbaki, Tag 00EK].
Algebra, VIII, p. 221, § 12. Tensor Products of Semisimple Modules
Let and be nonzero K-algebras. If the ring is simple (resp. semisimple), then the rings and are simple (resp. semisimple).
A ring B is semisimple (resp. simple) if and only if the B-module is semisimple (resp. isotypical and nonzero). The proposition therefore follows from Proposition 1 (VIII, p. 211).
Bourbaki sets the proof directly after the statement, and the corpus does not separate them, so what is above is the statement and its proof together.