Remove '-nightly' suffix from nightly build version number

It breaks our semver parsing, and the release channel is already 'nightly'.

.github/workflows/release_nightly.yml

@@ -81,12 +81,11 @@ jobs:
             - name: Limit target directory size
               run: script/clear-target-dir-if-larger-than 100
 
-            - name: Set release channel to nightly, add nightly prefix to the final version
+            - name: Set release channel to nightly
               run: |
                   set -eu
                   version=$(git rev-parse --short HEAD)
                   echo "Publishing version: ${version} on release channel nightly"
-                  sed -i '' "s/version = \"\(.*\)\"/version = \"\1-nightly\"/" crates/zed2/Cargo.toml
                   echo "nightly" > crates/zed/RELEASE_CHANNEL
 
             - name: Generate license file