src/print_battery_info.c 1024 char buffer is too small and can lead to numbers being cut in half

Tested i3status versions: 2.15 and main `d53da19a79d68b1dc9abdb953c3d2e0497b33a7a`
Kernel: 6.18.8-p1-asahi-dist
Architecture aarch64
GCC:
```
gcc (Gentoo 15.2.1_p20260214 p5) 15.2.1 20260214
Copyright (C) 2025 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
```

I've encountered this issue while setting up i3status on a new machine.
Estimated time on battery was surprisingly short and incorrect.

macsmc-battery driver reports it correctly
```
cat /sys/class/power_supply/macsmc-battery/uevent | grep EMPTY
POWER_SUPPLY_TIME_TO_EMPTY_NOW=44640
```
But value read from this line into i3status memory was incorrect. i3status only read first 2 digits discarding the rest of the line.
44640 was turning into 44.

I've found that just changing buffer size used by this part of the program was enough to allow i3status to read the whole number correctly.
https://github.com/i3/i3status/blob/d53da19a79d68b1dc9abdb953c3d2e0497b33a7a/src/print_battery_info.c#L150
https://github.com/i3/i3status/blob/d53da19a79d68b1dc9abdb953c3d2e0497b33a7a/src/print_battery_info.c#L163

This patch fixed the issue for me.
It's workaround at best and not a real solution, but it may be useful for somebody.

```
diff --git a/src/print_battery_info.c b/src/print_battery_info.c
index 1f56723..1ab0efc 100644
--- a/src/print_battery_info.c
+++ b/src/print_battery_info.c
@@ -147,7 +147,7 @@ static bool slurp_battery_info(battery_info_ctx_t *ctx, struct battery_info *bat
char *outwalk = buffer;

#if defined(__linux__)
- char buf[1024];
+ char buf[2048];
const char *walk, *last;
bool watt_as_unit = false;
int voltage = -1;
@@ -160,7 +160,7 @@ static bool slurp_battery_info(battery_info_ctx_t *ctx, struct battery_info *bat
return false;
}

- for (walk = buf, last = buf; (walk - buf) < 1024; walk++) {
+ for (walk = buf, last = buf; (walk - buf) < 2048; walk++) {
// `*walk` (slice of `buf`) is only initialised until `null` written by `slurp()`
if (*walk == '\0') {
break;
```