ci: bump setup-uv to maintained tag scheme (#696)

The old vX tags have been dropped to (force) (usually) better security practices. Dependabot will not update, however, leaving this v7 tag forever. Manually updating now.

See astral-sh/setup-uv#830

Committed via https://github.com/asottile/all-repos

Author: henryiii

.github/workflows/build.yml

@@ -97,7 +97,7 @@ jobs:
         with:
           fetch-depth: 0  # required for versioneer to find tags
 
-      - uses: astral-sh/setup-uv@v7
+      - uses: astral-sh/setup-uv@v8.0.0
         with:
           enable-cache: false
 
@@ -144,7 +144,7 @@ jobs:
 
     steps:
       - uses: actions/checkout@v6
-      - uses: astral-sh/setup-uv@v7
+      - uses: astral-sh/setup-uv@v8.0.0
         with:
           enable-cache: false