[js] Pin axios to exact 1.7.7 across all workspaces (#25560)

## Summary
- Adds a root-level `resolutions` field in `js/package.json` to force
all axios consumers (direct and transitive) to resolve to exactly
`1.7.7`
- Pins direct deps in ops, site, and uma-bridge from `^1.7.4` to exact
`1.7.7`
- Eliminates three separate axios versions (1.6.7, 1.6.8, 1.7.7) that
were being installed due to transitive deps from `@slack/webhook`,
`plaid`, and `wait-on`

## Why
Multiple axios versions cause unpredictable hoisting in the
`node-modules` linker — different workspaces could end up with different
axios versions at runtime depending on install order. Pinning guarantees
a single copy.

## Test plan
- [x] `yarn why axios` confirms all 6 consumers resolve to `1.7.7`
- [x] `yarn deps:check` (manypkg) passes
- [x] `yarn install` succeeds
- [x] `yarn format` passes

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
GitOrigin-RevId: fbcfeb70e0b84be5b50e9b383ce04acd7e5af635

Author: 2 people

package.json

@@ -65,6 +65,9 @@
       "built": false
     }
   },
+  "resolutions": {
+    "axios": "1.7.7"
+  },
   "engines": {
     "node": ">=18"
   },