http://www.wordreference.com/fren/maconnerie
Bricklaying if there is new construction to be done, masonry if they're repairing the structure.
You could leave out "package" as it doesn't really add anything.

Given your earlier question about "agglo", potentially this could be "blockwork package".

"Lesterose were appointed by main contractor Mace to carry out the BRICKWORK AND BLOCKWORK PACKAGE on Marlborough School and Commercial Building"
"Hi I'm doing a 26 storey project in Birmingham and now preparing the BLOCKWORK PACKAGE"
"Lee Marley has been awarded its first project for Laing O'Rourke, the Westgate Shopping Centre in Oxford. The internal BLOCKWORK PACKAGE is "


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Note added at 1 hr (2022-09-28 12:30:24 GMT)
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That said, I seem to remember seeing reference to stairs in your document. Is there a separate work package for floors? If not, and given that a "maçon" is simply a builder who will do you walls and floors, maybe you need to refer to the "structural works package" (even if not all the walls are necessarily loadbearing).

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Note added at 10 hrs (2022-09-28 22:25:35 GMT)
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I wanted to put this under Discussion but I'm too longwinded and it won't fit in the box.
Difference between maçonnerie & masonry
Let's look at what is meant and/or understood by 'maçonnerie' and 'masonry'. In principle, it refers to VERTICAL construction using discrete units of stone, dried mud (originally) or similar (subsequently: bricks, concrete blocks, etc.). Since it days gone by it was not easy or possible to use small units such as these for horizontal construction, historically the terms are not commonly applied to floors. An exception to this is the vaulting of churches and castles, where the vertical gradually approaches the horizontal, without ever actually reaching it.
'Maçon' (but not 'mason') is a term in general use for a 'builder', whether he uses bricks, stone units, or concrete blocks (and the growth in timber construction has even given rise to the term 'maçon charpentier'). Thus, Dicobat tells us that "Le maçon exécute les travaux connexes [à tout ce qui constitue la maçonnerie] tels que fondations, dallages, poutres et planchers de béton, chapes, ravelements et jointoiements de pierre, cloisons intérieures". This is not the case for the English 'mason' who is "A tradesman who cuts stone [typically a monumental mason; 'marbrier (funéraire)'] or sets stonework. In Scotland or the USA, a bricklayer is usually also a mason. He is generally in England either a fixer or a walling mason."
In short, mason/maçon and masonry/maçonnerie are false friends ("Today in the UK 'masonry' usually has the more limited meaning of work with cut stones"). Since in French, a 'maçon' can also build concrete floors, beams and foundation slabs, it is entirely possible that the "lot maçonnerie" includes such work. The English 'masonry' does not cover that.