Rework lighthouse_version to reduce spurious recompilation (#8336)

#8311


  Removes the `git_version` crate from `lighthouse_version` and implements git `HEAD` tracking manually.
This removes the (mostly) broken dirty tracking but prevents spurious recompilation of the `lighthouse_version` crate.

This also reworks the way crate versions are handled by utilizing workspace version inheritance and Cargo environment variables.
This means the _only_ place where Lighthouse's version is defined is in the top level `Cargo.toml` for the workspace. All relevant binaries then inherit this version. This largely makes the  `change_version.sh` script useless so I've removed it, although we could keep a version which just alters the workspace version (if we need to maintain compatibility with certain build/release tooling.

### When is a Rebuild Triggered?

1. When the build.rs file is changed.
2. When the HEAD commit changes (added, removed, rebased, etc)
3. When the branch changes (this includes changing to the current branch, and creating a detached HEAD)

Note that working/staged changes will not trigger a recompile of `lighthouse_version`.


Co-Authored-By: Mac L <mjladson@pm.me>

Co-Authored-By: Michael Sproul <michael@sigmaprime.io>

common/lighthouse_version/src/lib.rs

@@ -1,49 +1,25 @@
-use git_version::git_version;
 use std::env::consts;
 
 /// Returns the current version of this build of Lighthouse.
 ///
-/// A plus-sign (`+`) is appended to the git commit if the tree is dirty.
 /// Commit hash is omitted if the sources don't include git information.
 ///
 /// ## Example
 ///
-/// `Lighthouse/v1.5.1-67da032+`
-pub const VERSION: &str = git_version!(
-    args = [
-        "--always",
-        "--dirty=+",
-        "--abbrev=7",
-        // NOTE: using --match instead of --exclude for compatibility with old Git
-        "--match=thiswillnevermatchlol"
-    ],
-    prefix = "Lighthouse/v8.0.0-rc.2-",
-    fallback = "Lighthouse/v8.0.0-rc.2"
-);
+/// `Lighthouse/v8.0.0-67da032`
+pub const VERSION: &str = env!("GIT_VERSION");
 
 /// Returns the first eight characters of the latest commit hash for this build.
 ///
 /// No indication is given if the tree is dirty. This is part of the standard
 /// for reporting the client version to the execution engine.
-pub const COMMIT_PREFIX: &str = git_version!(
-    args = [
-        "--always",
-        "--abbrev=8",
-        // NOTE: using --match instead of --exclude for compatibility with old Git
-        "--match=thiswillnevermatchlol"
-    ],
-    prefix = "",
-    suffix = "",
-    cargo_prefix = "",
-    cargo_suffix = "",
-    fallback = "00000000"
-);
+pub const COMMIT_PREFIX: &str = env!("GIT_COMMIT_PREFIX");
 
 /// Returns `VERSION`, but with platform information appended to the end.
 ///
 /// ## Example
 ///
-/// `Lighthouse/v1.5.1-67da032+/x86_64-linux`
+/// `Lighthouse/v8.0.0-67da032/x86_64-linux`
 pub fn version_with_platform() -> String {
     format!("{}/{}-{}", VERSION, consts::ARCH, consts::OS)
 }
@@ -52,16 +28,16 @@ pub fn version_with_platform() -> String {
 ///
 /// ## Example
 ///
-/// `1.5.1`
+/// `8.0.0`
 pub fn version() -> &'static str {
-    "8.0.0-rc.2"
+    env!("SEMANTIC_VERSION")
 }
 
 /// Returns the name of the current client running.
 ///
 /// This will usually be "Lighthouse"
 pub fn client_name() -> &'static str {
-    "Lighthouse"
+    env!("CLIENT_NAME")
 }
 
 #[cfg(test)]
@@ -72,7 +48,7 @@ mod test {
     #[test]
     fn version_formatting() {
         let re = Regex::new(
-            r"^Lighthouse/v[0-9]+\.[0-9]+\.[0-9]+(-(rc|beta).[0-9])?(-[[:xdigit:]]{7})?\+?$",
+            r"^Lighthouse/v[0-9]+\.[0-9]+\.[0-9]+(-(rc|beta)\.[0-9])?(-[[:xdigit:]]{7})?$",
         )
         .unwrap();
         assert!(
@@ -91,4 +67,14 @@ mod test {
             version()
         );
     }
+
+    #[test]
+    fn client_name_is_lighthouse() {
+        assert_eq!(client_name(), "Lighthouse");
+    }
+
+    #[test]
+    fn version_contains_semantic_version() {
+        assert!(VERSION.contains(version()));
+    }
 }