doc: disambiguate pseudo-code statement

the statement `set Y to be the file system root` can be wrongly
interpreted as the file system root being updated to match Y,
removing the `be` term removes this potential interpretation

PR-URL: #57092
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>

Author: dario-piotrowicz

doc/api/modules.md

@@ -342,7 +342,7 @@ require(X) from module at path Y
    a. return the core module
    b. STOP
 2. If X begins with '/'
-   a. set Y to be the file system root
+   a. set Y to the file system root
 3. If X begins with './' or '/' or '../'
    a. LOAD_AS_FILE(Y + X)
    b. LOAD_AS_DIRECTORY(Y + X)