chore: Update lambda-promtail nix checksum

[paul1r]

What this PR does / why we need it: This PR updated some packages for lambda-promtail, resulting in subsequent errors when doing the nix check.

This PR adjusts the checksum to the proper value.

nix results before this PR:

% nix build
error: hash mismatch in fixed-output derivation '/nix/store/z9p2ls5wj3ga76315c6zfpqzj39hqkvk-lambda-promtail-275b768b-go-modules.drv':
         specified: sha256-GM7tXlN7t7c3EHtF4vMzhINIZm+HQpyMYVAv3Dtiny8=
            got:    sha256-fG+AJfniGJy9fpD2Jluh7N2FDYt9LCjXCVoWktuvus0=
error: 1 dependencies of derivation '/nix/store/dlsvh3gi9kjhyrawfycnrj1apcg0vn25-lambda-promtail-275b768b.drv' failed to build
error: 1 dependencies of derivation '/nix/store/albijd5i0h2q0pz58c97xjaz5ylgir6i-loki-275b768b.drv' failed to build

Results after this PR:

git status
On branch paul1r/update_lambda_promtailflake_again
Your branch is up to date with 'origin/paul1r/update_lambda_promtailflake_again'.

nothing to commit, working tree clean
progers@Pauls-MacBook-Pro loki % nix build
progers@Pauls-MacBook-Pro loki % 

Which issue(s) this PR fixes: Fixes #

Special notes for your reviewer:

Checklist

• [X] Reviewed the CONTRIBUTING.md guide (required)
• [ ] Documentation added
• [ ] Tests updated
• [X] Title matches the required conventional commits format, see here
  • Note that Promtail is considered to be feature complete, and future development for logs collection will be in Grafana Alloy. As such, feat PRs are unlikely to be accepted unless a case can be made for the feature actually being a bug fix to existing behavior.
• [ ] Changes that require user attention or interaction to upgrade are documented in docs/sources/setup/upgrade/_index.md
• [ ] If the change is deprecating or removing a configuration option, update the deprecated-config.yaml and deleted-config.yaml files respectively in the tools/deprecated-config-checker directory. Example PR