[stable25] Fix compilation of Vue 2.7 features

[Pytal]

• For [BITV/A11Y Instance] Contacts menu styles #36623

Summary

The :deep() selector, introduced in Vue 2.7 alongside the deprecation of ::v-deep and subsequent un-deprecation in this commit vuejs/vue@2f335b2 released in Vue 2.7.11 https://github.com/vuejs/vue/blob/main/CHANGELOG.md#2711-2022-10-11, was not being compiled correctly and resulted in incorrect CSS output

/* Before */
#contactsmenu-menu:deep .emptycontent[data-v-e32bb484] {...
/* After */
#contactsmenu-menu[data-v-e32bb484] .emptycontent {...

We must explicitly bump vue-loader to 15.10.1 on stable25 as https://github.com/vuejs/vue-loader/releases/tag/v15.10.0 introduced support for Vue 2.7

This is needed on stable25 but not master as although both have vue-loader 15.9.8

server/package.json

Line 143 in d60fd2c

"vue-loader": "^15.9.8",

server/package.json

Line 167 in 08802ad

"vue-loader": "^15.9.8",

, @nextcloud/webpack-vue-config is present

server/package.json

Line 122 in 08802ad

"@nextcloud/webpack-vue-config": "github:nextcloud/webpack-vue-config#master",

only on master which results in vue-loader being deduped to 15.10.1

This fixes the contacts menu styles

Before	After

Checklist

• Code is properly formatted
• Sign-off message is added to all commits
• Tests (unit, integration, api and/or acceptance) are included
• Screenshots before/after for front-end changes
• Documentation (manuals or wiki) has been updated or is not required
• Backports requested where applicable (ex: critical bugfixes)

[szaimen]

Lgtm but didnt test