Invalid sha256sum on tag 3.4.2 is causing build to fail.

Hello,
I tried to build docker image with tag 3.4.2 but failed due to checksum error.

```
17:38:32 + KONG_REPO=34
17:38:32 + DOWNLOAD_URL=https://packages.konghq.com/public/gateway-34/rpm/el/8/x86_64/kong-3.4.2.el8.x86_64.rpm
17:38:32 + curl -fL https://packages.konghq.com/public/gateway-34/rpm/el/8/x86_64/kong-3.4.2.el8.x86_64.rpm -o /tmp/kong.rpm
17:38:32 % Total % Received % Xferd Average Speed Time Time Time Current
....
17:38:39 + echo '46dcb86e1af3d8dd32ff1e679befad2ef11975039effcf94f7d9b46b84b4c3ce /tmp/kong.rpm'
17:38:39 + sha256sum -c -
17:38:39 /tmp/kong.rpm: FAILED
17:38:39 sha256sum: WARNING: 1 computed checksum did NOT match
```

So, I downloaded the package manually to verify the checksum.
```
#https://packages.konghq.com/public/gateway-34/rpm/el/8/x86_64/kong-3.4.2.el8.x86_64.rpm
sha256sum kong-3.4.2.el8.x86_64.rpm
01800f0664196f6f93b408c693653e248917ff1e8eadc35bda165c4ca920c266 kong-3.4.2.el8.x86_64.rpm
```
Current checksum value on tag 3.4.2
https://github.com/Kong/docker-kong/blob/e07de903edf213445a0540172d51529ac344b448/Dockerfile.rpm#L21

Start at Dockerfile.rpm line 21 and compare the checksum used there with the package downloaded from the reported Kong repository URL. Run the relevant Docker image build for tag 3.4.2 and confirm that checksum verification passes and the build completes.

Written by the indexing model from the issue text.