GLCI [test-win-dev][test-win-rel]: Fail to install with 'gcc not found'

[MichaelChirico]

Links to jobs:

https://gitlab.com/Rdatatable/data.table/-/jobs/7949158879
https://gitlab.com/Rdatatable/data.table/-/jobs/7949158861

Links to 00install.out:

https://gitlab.com/Rdatatable/data.table/-/jobs/7949158879/artifacts/file/bus/test-win-dev/data.table.Rcheck/00install.out
https://gitlab.com/Rdatatable/data.table/-/jobs/7949158861/artifacts/file/bus/test-win-rel/data.table.Rcheck/00install.out

One 00install.out:

* installing *source* package 'data.table' ...
** using staged installation

   **********************************************
   WARNING: this package has a configure script
         It probably needs manual configuration
   **********************************************


** libs
gcc  -I"C:/R/include" -DNDEBUG     -I"c:/rtools44/x86_64-w64-mingw32.static.posix/include"   -fopenmp   -O2 -Wall  -mfpmath=sse -msse2 -mstackrealign  -c assign.c -o assign.o
/bin/sh: line 1: gcc: command not found
make: *** [C:/R/etc/x64/Makeconf:290: assign.o] Error 127
ERROR: compilation failed for package 'data.table'
* removing 'C:/GitLab-Runner/builds/Rdatatable/data.table/data.table.Rcheck/data.table'