sync: update CI config files

We allocate once via "make([]byte, len)",
and again when that buffer is converted to a string.

Thankfully, since Go 1.10 we have strings.Builder,
designed specifically for this use case.

In a downstream benchmark in go-car,
which needs to reconstruct many CID values,
we see small but nice gains:

    name           old time/op    new time/op    delta
    ReadBlocks-16    1.09ms ± 4%    1.06ms ± 5%   -3.33%  (p=0.007 n=11+11)

    name           old speed      new speed      delta
    ReadBlocks-16   478MB/s ± 4%   494MB/s ± 5%   +3.46%  (p=0.007 n=11+11)

    name           old alloc/op   new alloc/op   delta
    ReadBlocks-16    1.30MB ± 0%    1.25MB ± 0%   -3.86%  (p=0.000 n=12+12)

    name           old allocs/op  new allocs/op  delta
    ReadBlocks-16     9.50k ± 0%     8.45k ± 0%  -11.05%  (p=0.000 n=12+12)

Add benchmarks that compare two ways of checking for
`multihash.IDENTITY` code:
1. `Cid.Prefix().MhType`
2. Decode of `Cid.Hash()`

This benchmark illustrates that using Cid.Prefix is more efficient than
`multihash.Decode`. Users wishing to perform such a check should use
`Cid.Prefix`.

Consider that `Cid.Prefix` is already efficient enough and introducing a
dedicated API for performing this check will likely result in small
gains.

Relates to #133

* add version.json file

* update .github/workflows/go-test.yml

* update .github/workflows/go-check.yml

* add .github/workflows/releaser.yml

* add .github/workflows/release-check.yml

* add .github/workflows/tagpush.yml

Co-authored-by: web3-bot <web3-bot@users.noreply.github.com>

* refactor: remove Codecs table
* chore: go-cid 0.2.0

Codec table was missing dag-json and it had invalid code for dag-cbor.
It also had invalid string representation of dag-pb -- it was using
'protobuf' which is a totally different code.

This removes invalid mappings entirely.
https://github.com/multiformats/go-multicodec should be used instead.