chore: update all dependencies

[bekvbe]

Summary

Stacked on #1200 (GHA + Node 22). Brings every dependency current:

Runtime deps

• isomorphic-fetch 2.2.1 → 3.0.0 — retires the ancient node-fetch v1 fallback (pre-Node-18 consumers get node-fetch v2; Node 18+ uses native fetch as before)
• promise-retry 1.1.1 → 2.0.1, @babel/runtime → latest 7.x, lodash → 4.18
• Babel stays on 7.x on purpose — @babel/runtime 8.0.0 requires migrating the whole build chain to Babel 8, out of scope here

Dev deps

• typescript 4.3 → 6.0 with @goodeggs/tsconfig 1 → 2 and @goodeggs/toolkit 7 → 8
• mocha 11, nyc 18, leasot 14, @types/node 22, latest @types/* (@types/node-fetch stays v2 to match what isomorphic-fetch 3 uses)
• Removed flow-bin — nothing references it (build:types runs tsc); it was 80+ releases stale

Type fallout (no runtime behavior changes)

• TS 6 no longer auto-includes @types packages → explicit types list in tsconfig; skipLibCheck for third-party declaration hygiene
• catch variables are unknown under modern strict mode → annotated where the code mutates errors (the existing err.retryCount/err.name pattern; 13 lint warnings for no-explicit-any, no errors)
• Test fetch spy/stub types use Parameters<typeof fetch> instead of the DOM-lib RequestInfo global
• getRequestOptions return cast documents that it intentionally passes node-fetch extension options (timeout, agent) not present in RequestInit

Not changed: engines stays >=12 — the shipped (transpiled) code is unchanged, so no reason to force a breaking engine bump on consumers.

Test plan

• Full yarn test green on Node 22: 35 passing, 0 failing; typecheck 0 errors; lint 0 errors
• yarn build (transpile + declarations) succeeds
• CI passes

Note for reviewers

@goodeggs/toolkit/@goodeggs/tsconfig metadata on npm.goodeggs.com requires auth that yarn 1 fails to send from ~/.npmrc scope config — updating those two needed a temporary project-local token line (not committed; verified no token in the diff). Existing lockfile installs are unaffected.