MISC: Do not round return value of getBonusTime APIs

[catloversg]

This PR implements the change mentioned at #1924 (comment).

For more information, please check that issue and https://discord.com/channels/415207508303544321/415213413745164318/1332268782735065171.

Test code:

/** @param {NS} ns */
async function loopBBNextUpdate(ns) {
  while (true) {
    await ns.bladeburner.nextUpdate();
    console.log(new Date().toISOString(), "BB nextUpdate");
  }
}

/** @param {NS} ns */
export async function main(ns) {
  ns.clearLog();
  console.clear();
  await ns.bladeburner.nextUpdate();
  Player.bladeburner.storedCycles = 0; // debug code
  loopBBNextUpdate(ns);
  while (true) {
    console.log(new Date().toISOString(), ns.bladeburner.getBonusTime(), Player.bladeburner.storedCycles)
    await ns.asleep(100);
  }
}

Before:

After: