fix(uniffi): drop unneeded contents:write permission on workflow jobs

The CodeQL autofix landed in #1078 added `permissions: contents: read`
at the top level of uniffi-packages.yml, which then forbids any
nested job (including the called workflow uniffi-swift.yml) from
requesting higher permissions — workflow validation fails with:

  Error calling workflow ... The nested job 'build-and-publish' is
  requesting 'contents: write', but is only allowed 'contents: read'.

Neither job actually needs write: `gh release list` in resolve-tag is
read-only, and the publish step authenticates to the hosting repo
with UNIFFI_XCFRAMEWORK_PAT (not GITHUB_TOKEN). Drop the elevation
on both so the workflow can start.

Author: pblazej

.github/workflows/uniffi-packages.yml

@@ -32,8 +32,6 @@ env:
 jobs:
   resolve-tag:
     runs-on: ubuntu-latest
-    permissions:
-      contents: write
     outputs:
       tag_name: ${{ steps.get-tag.outputs.tag_name }}
       version: ${{ steps.get-tag.outputs.version }}

.github/workflows/uniffi-swift.yml

@@ -38,7 +38,7 @@ jobs:
     name: Build & publish Swift xcframework
     runs-on: macos-26
     permissions:
-      contents: write
+      contents: read
     steps:
       - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
         with: