Deployment preparation: `StakelessGaugeCheckpointer` V2

[jubeira]

Deployment preparation: StakelessGaugeCheckpointer V2

build-info: https://github.com/balancer/balancer-v2-monorepo/commit/fc3e5735a07438ab506931f56adf64dede1441b1

Deployment preparation tasks checklist:

• [x] Deployments README is updated with the new task name and link
• [x] Task README has a description and links to the artifacts
• [x] build-info is updated with artifacts compiled at the specified commit
• [x] Artifacts are generated from build-info
• [x] New task has a working fork test

Deprecating old tasks checklist:

• [x] Old task was moved to deprecated/ directory
• [x] Deployments README is updated: old task is moved to the 'deprecated' section, and links are updated with the deprecated/ prefix
• [x] Old task imports in index.ts, input.ts and fork tests are updated
• [x] Old task README is updated with a warning sign, a link to the replacement task and a short description

Code checklist:

• [x] The diff is legible and has no extraneous changes
• [x] Complex code has been commented in tests and scripts
• [x] Fork test block number and test cases are appropriate for this deployment
• [x] The base branch is either master, or there's a description of how to merge

Issue Resolution

N/A