fix(docs): add required permissions for build:docs

[jamietanna]

Changes

As it currently fails because we only have contents:read i.e.

ERROR: Error getting query results
       "err": {
         "cmd": "/bin/sh -c gh issue list --json \"title,number,url,labels\" --search \"type:Bug\" --limit 1000",
         "stderr": "gh: To use GitHub CLI in automation, set the GH_TOKEN environment variable.\n",
         "stdout": "",
         "options": {
           "encoding": "utf-8",
           "env": ["CI", "HOME", "PATH", "LANG"],
           "maxBuffer": 10485760,
           "timeout": 900000
         },
         "exitCode": 4,
         "name": "ExecError",
         "message": "Command failed: gh issue list --json \"title,number,url,labels\" --search \"type:Bug\" --limit 1000\ngh: To use GitHub CLI in automation, set the GH_TOKEN environment variable.\n",
         "stack": "ExecError: Command failed: gh issue list --json \"title,number,url,labels\" --search \"type:Bug\" --limit 1000\ngh: To use GitHub CLI in automation, set the GH_TOKEN environment variable.\n\n    at ChildProcess.<anonymous> (/home/runner/work/renovate/renovate/lib/util/exec/common.ts:120:11)\n    at ChildProcess.emit (node:events:520:35)\n    at ChildProcess.emit (node:domain:489:12)\n    at ChildProcess._handle.onexit (node:internal/child_process:294:12)"
       }
ERROR: Unexpected error
       "err": {
         "cmd": "/bin/sh -c gh issue list --json \"title,number,url,labels\" --search \"type:Bug\" --limit 1000",
         "stderr": "gh: To use GitHub CLI in automation, set the GH_TOKEN environment variable.\n",
         "stdout": "",
         "options": {
           "encoding": "utf-8",
           "env": ["CI", "HOME", "PATH", "LANG"],
           "maxBuffer": 10485760,
           "timeout": 900000
         },
         "exitCode": 4,
         "name": "ExecError",
         "message": "Command failed: gh issue list --json \"title,number,url,labels\" --search \"type:Bug\" --limit 1000\ngh: To use GitHub CLI in automation, set the GH_TOKEN environment variable.\n",
         "stack": "ExecError: Command failed: gh issue list --json \"title,number,url,labels\" --search \"type:Bug\" --limit 1000\ngh: To use GitHub CLI in automation, set the GH_TOKEN environment variable.\n\n    at ChildProcess.<anonymous> (/home/runner/work/renovate/renovate/lib/util/exec/common.ts:120:11)\n    at ChildProcess.emit (node:events:520:35)\n    at ChildProcess.emit (node:domain:489:12)\n    at ChildProcess._handle.onexit (node:internal/child_process:294:12)"
       }

Follow-up to #39801

Context

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🎉 This PR is included in version 42.38.1 🎉

The release is available on:

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• 42.38.1

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