Use `globalThis` instead of bare `global` in utils (#4380)

## Description

`isTestEnv` and `isRemoteDebuggingEnabled` read the bare `global`, which
is React Native/Node-specific and doesn't exist in browsers — `utils.ts`
is shared code that also runs on web. Both now use the standard
`globalThis`, available in every runtime.

To keep the pattern from coming back, a lint rule
(`no-restricted-globals` scoped to `src/v3/**`, `src/web/**`, and root
`src/*.ts`) now errors on any bare `global` reference in those files,
with `globalThis` named in the message. `declare global`
type-declaration blocks are unaffected (the rule counts scope
references, not the TS keyword).

## Test plan

- `yarn ts-check` clean; `yarn test` 103/103 (`isTestEnv` is exercised
by every v3 hook test via the `disableReanimated` default;
`isRemoteDebuggingEnabled` runs during handler creation) — no regression
under RN/Node, where `globalThis === global`
- Browser A/B probe (esbuild bundle of `src/utils.ts`, no bundler shims,
WebKit): the new `globalThis` implementations return correct values; the
old bare-`global` implementations throw `ReferenceError: Can't find
variable: global`
- Lint rule verified: baseline clean, fires with the actionable message
on a violation, `declare global` blocks in `globals.ts`/`global.d.ts`
unaffected