Implement LogOutputChannel to improve logging

[JustinGrote]

Updates the logging API to use LogOutputChannel for automatic severities, user-selectible log levels, and better log management.

[Copilot]

Pull Request Overview

This PR implements LogOutputChannel for logging improvements, updates the ESLint configuration, and bumps the Node version for the CI builds while also refactoring several TypeScript error workarounds.

• Replace old logging functions in src/log.ts with LogOutputChannel methods.
• Update ESLint config and build workflow (Node version bump).
• Add/adjust ts-expect-error comments and reformat constructors in various modules to improve type checking with newer TypeScript rules.

Reviewed Changes

Copilot reviewed 21 out of 26 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
eslint.config.mjs	Introduces a flat ESLint configuration with custom ignore patterns.
src/log.ts	Refactors logging to use vscode.LogOutputChannel with specific log methods.
.github/workflows/build.yml	Updates node-version from 16.x to 20.x.
src/store/workflowRun.ts	Adds ts-expect-error comments for Octokit-related API calls.
src/pinnedWorkflows/pinnedWorkflows.ts	Introduces ts-expect-error comments and maps workflows by path.
src/treeViews/icons.ts	Refactors functions to return proper types (e.g. undefined instead of "").
src/treeViews/settings/repoSecretsNode.ts	Adds ts-expect-error comments around repo secrets API calls.
src/treeViews/settings/environmentSecretsNode.ts	Updates constructor formatting and adds ts-expect-error comments.
src/treeViews/settings/environmentVariablesNode.ts	Updates constructor formatting and adds ts-expect-error comments.
src/commands/openWorkflowFile.ts	Simplifies error handling by removing unused error parameter in catch.
src/treeViews/settings/repoVariablesNode.ts	Adds ts-expect-error comments for repo variables API calls.
src/treeViews/shared/previousAttemptsNode.ts	Reformats constructor definition for clarity.
src/treeViews/shared/attemptNode.ts	Reformats constructor definition for clarity.
src/treeViews/current-branch/currentBranchRepoNode.ts	Reformats constructor definition for clarity.
src/treeViews/settings/environmentNode.ts	Reformats constructor definition for clarity.

Files not reviewed (5)

• .eslintrc.json: Language not supported
• .prettierrc.json: Language not supported
• .vscode/extensions.json: Language not supported
• .vscode/settings.json: Language not supported
• package.json: Language not supported

Comments suppressed due to low confidence (2)

eslint.config.mjs:13

• [nitpick] Consider renaming 'globalignores' to 'globalIgnores' for better readability and consistency with typical camelCase naming conventions.

name: "globalignores",

src/treeViews/settings/repoVariablesNode.ts:19

• [nitpick] The comment refers to 'octokit bump' in lowercase. For consistency, consider capitalizing it to 'Octokit bump'.

// @ts-expect-error FIXME: Type error after newer rules available. This will be fixed in octokit bump