Remove several unneeded static_casts to uint64_t

11 jobs for 135-make-chunk-computations-constexpr in 11 minutes and 27 seconds (queued for 3 seconds)
Status Job ID Name Coverage
  Check Format
passed #12848
check format

00:00:12

 
  Build Deps
passed #12849
compile dependencies

00:00:53

 
  Build
passed #12850
compile GekkoFS

00:04:04

passed #12851
compile tests

00:00:19

 
  Test
passed #12852
integration tests

00:06:17

passed #12855
test directories

00:00:25

passed #12858
test lseek

00:00:24

passed #12857
test path resolution

00:00:24

passed #12856
test truncate

00:00:24

passed #12854
test wr

00:00:25

passed #12853
unit

00:00:26