config(lido-withdrawals): add missing timer, fix type

[PetarKirov]

Re-submitting PR #216, since GH Actions has does not provide CI secrets to workflows from forks.

Because of missing Type=oneshot the service keeps failing when system is
being activated with error like this:

🚀 Lido Withdrawals Automation developed by Stakely.io - 2023 v1.0.1
Step 1: Checking environment variables and asking for missing values...
Cannot read properties of undefined (reading 'trim')

Signed-off-by: Jakub Sokołowski [email protected]

[github-actions]

Thanks for your Pull Request!

Below you will find a summary of the cachix status of each package, for each supported platform.

package	x86_64-linux	x86_64-darwin	aarch64-darwin
cachix	❌ build failed	🚫 not supported	🚫 not supported
dcd	✅ cached	🚫 not supported	🚫 not supported
dmd	✅ cached	🚫 not supported	🚫 not supported
dscanner	✅ cached	🚫 not supported	🚫 not supported
dub	✅ cached	🚫 not supported	🚫 not supported
folder-size-metrics	✅ cached	🚫 not supported	🚫 not supported
foundry	✅ cached	🚫 not supported	🚫 not supported
geth	✅ cached	🚫 not supported	🚫 not supported
grafana-agent	✅ cached	🚫 not supported	🚫 not supported
ldc	✅ cached	🚫 not supported	🚫 not supported
lido-withdrawals-automation	✅ cached	🚫 not supported	🚫 not supported
mcl	✅ cached	🚫 not supported	🚫 not supported
mev-boost	✅ cached	🚫 not supported	🚫 not supported
nethermind	✅ cached	🚫 not supported	🚫 not supported
nimbus	✅ cached	🚫 not supported	🚫 not supported
nix	❌ build failed	🚫 not supported	🚫 not supported
nix-eval-jobs	❌ build failed	🚫 not supported	🚫 not supported
nix-fast-build	❌ build failed	🚫 not supported	🚫 not supported
pyroscope	✅ cached	🚫 not supported	🚫 not supported
random-alerts	✅ cached	🚫 not supported	🚫 not supported
rustToolchain	✅ cached	🚫 not supported	🚫 not supported
serve-d	✅ cached	🚫 not supported	🚫 not supported
terraform	✅ cached	🚫 not supported	🚫 not supported
terranix	✅ cached	🚫 not supported	🚫 not supported
validator-ejector	✅ cached	🚫 not supported	🚫 not supported
web3signer	✅ cached	🚫 not supported	🚫 not supported