docs: update the test action path (#11919)

HI there, I found that the old testcase is deleted in the repo now. So
here is my advice

1 used the old link with commit hash
2 delete the link

Im using the first solution now.

docs/programmers_guide/witness_formal_spec.md

@@ -585,7 +585,7 @@ format: `ACCOUNT_LEAF key:[]byte flags [nonce:uint64] [balance:[]byte]`
 
 encoded as `[ 0x05 CBOR(ENCODE_KEY(key))... flags /CBOR(nonce).../ /CBOR(balance).../ ]`
 
-*flags* is a bitset encoded in a single bit (see [`witness_operators_test.go`](../../trie/witness_operators_test.go) to see flags in action).
+*flags* is a bitset encoded in a single bit (see [`witness_operators_test.go`](https://github.com/erigontech/erigon/blob/adf52465e3fd67a76a52c7214b20dcbe15182b98/turbo/trie/witness_operators_test.go) to see flags in action).
 * bit 0 defines if **code** is present; if set to 1, then `has_code=true`;
 * bit 1 defines if **storage** is present; if set to 1, then `has_storage=true`;
 * bit 2 defines if **nonce** is not 0; if set to 0, *nonce* field is not encoded;