Update dependencies (consolidate open Dependabot PRs) (#2913)

Consolidates all open Dependabot PRs into a single update so they can be
closed.

### Go (`go.mod`/`go.sum`)
- `go.opentelemetry.io/otel` + `otel/sdk` (and related otel modules)
1.44.0 → 1.45.0 (#2869, #2577)
- Already at or above the target on master, so no change needed:
`golang.org/x/crypto` (#2715), `golang.org/x/net` (#2708),
`github.com/go-jose/go-jose/v4` (#2533)

### dashboard/client
- `next` + `@next/bundle-analyzer` 15.5.24 → 16.3.x, `postcss` → 8.5.28
(#2762)
- Next.js 16 removed `serverRuntimeConfig` / `next/config`, so
`pages/api/[...slug].js` now reads `process.env.SERVER_URL` directly
(same `http://localhost:8080` default). `tsconfig.json` gets the `jsx:
react-jsx` setting that Next 16 requires.
- `query-string` 7 → 9.5.1, `decode-uri-component` → 0.5.0 (#2833)
- `lodash` → 4.18.1 (#2527), `http-proxy-middleware` → 2.0.10 (#2690)
- Transitive: `brace-expansion` 2.1.7 (#2905), `browserslist` 4.29.3
(#2839), `postcss-selector-parser` 6.1.4 (#2837), `nanoid` 3.3.19
(#2785), `ws` 7.5.13 (#2687), `follow-redirects` 1.16.1 (#2552),
`picomatch` 2.3.2 (#2512), `yaml` 1.10.3 / 2.9.1 (#2511), `immutable`
5.1.9 (#2494), `minimatch` 9.0.9 (#2479), `glob` 10.5.0 (#2406)
- `micromatch` is already at 4.0.8, and `yarn.lock` no longer exists
(#2028)

### mintlify
- `mint` → 4.2.970 (#2788, #2782), which brings `postcss` 8.5.23 and
`js-yaml` 4.3.1
- Transitive: `ip-address` 10.7.3 (#2894), `nanoid` 3.3.19 (#2787),
`brace-expansion` 1.1.21 (#2773), `socket.io-parser` 4.2.7 (#2760),
`body-parser` 1.20.8 (#2735)

### actions
- `bcr-pr-reviewer`, `release-helper`: `@actions/core` → 1.11.1, which
drops `uuid` (#2575, #2574). For `bcr-pr-reviewer`, the checked-in
`node_modules` is updated too: `@actions/{core,exec,io}` are refreshed
and `uuid` is removed.
- `cherry_picker`, `update-lockfile`: `requests` 2.32.4 → 2.33.0 (#2516,
#2515). `buildkite/docker/ubuntu1604` no longer exists (#2513).

### agent
- `bytes` 1.4.0 → 1.11.1 in `Cargo.lock` (#2453)

### Testing
- `go build ./...`
- `next build` for dashboard/client
- `mint version` for mintlify
- `node --test` for actions/bcr-pr-reviewer (21/21 pass)

Closes #2905, #2894, #2869, #2839, #2837, #2833, #2788, #2787, #2785,
#2782, #2773, #2762, #2760, #2735, #2715, #2708, #2690, #2687, #2577,
#2575, #2574, #2552, #2533, #2527, #2516, #2515, #2513, #2512, #2511,
#2494, #2479, #2453, #2406, #2028