ehance(installer): use ldflags to inject versions

Instead of the CI/CD using sed to replace the 'replaceme' text we can instead use ldflags which can inject variables at build time to the versions. The makefile had a bunch of workarounds for dev so these have been removed to cleanup etc etc and fetchs versions from the gh api directly if the variables are not injected like the CI/CD does

install/main.go

@@ -2,12 +2,12 @@ package main
 
 import (
 	"bufio"
+	"crypto/rand"
 	"embed"
+	"encoding/base64"
 	"fmt"
 	"io"
 	"io/fs"
-	"crypto/rand"
-	"encoding/base64"
 	"net"
 	"net/http"
 	"net/url"
@@ -20,11 +20,17 @@ import (
 	"time"
 )
 
-// DO NOT EDIT THIS FUNCTION; IT MATCHED BY REGEX IN CICD
+// Version variables injected at build time via -ldflags
+var (
+	pangolinVersion string
+	gerbilVersion   string
+	badgerVersion   string
+)
+
 func loadVersions(config *Config) {
-	config.PangolinVersion = "replaceme"
-	config.GerbilVersion = "replaceme"
-	config.BadgerVersion = "replaceme"
+	config.PangolinVersion = pangolinVersion
+	config.GerbilVersion = gerbilVersion
+	config.BadgerVersion = badgerVersion
 }
 
 //go:embed config/*