Delete non-reduced fuzz inputs

[maflcko]

Can be reproduced with:

apt update && apt install wget -y
wget https://raw.githubusercontent.com/bitcoin-core/bitcoin-maintainer-tools/master/delete_nonreduced_fuzz_inputs.sh
bash delete_nonreduced_fuzz_inputs.sh

(needs a full vm, docker or privileged podman)

This deletes 128 782 files

Similar to the last one: #44

Fixes #56
Might fix google/oss-fuzz#5920 (comment)
Might fix the bitcoinbuilds ci fuzz timeout

[practicalswift]

ACK fbb36d7: less is more in this case

[maflcko]

This was done on an AMD EPYC Processor. Diff for repeated runs:

• AMD EPYC (inverse order: first fuzzer,address,undefined,integer then fuzzer ): 53519 files
• Intel Xeon Processor: 11980 files
• Intel(R) Core(TM) i7-7700HQ: 24567 files