cargo: bump zerocopy from 0.8.40 to 0.8.48 in /src/exercises/bare-metal/rtc in the patch group (#3140)

Bumps the patch group in /src/exercises/bare-metal/rtc with 1 update:
[zerocopy](https://github.com/google/zerocopy).

Updates `zerocopy` from 0.8.40 to 0.8.48

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

src/exercises/bare-metal/rtc/Cargo.lock

@@ -17,4 +17,4 @@ log = "0.4.29"
 safe-mmio = "0.2.7"
 smccc = "0.2.2"
 spin = "0.10.0"
-zerocopy = "0.8.37"
+zerocopy = "0.8.48"