Fix pg_lake install check for main/master versions

Update check_pg_lake to properly verify installation even for main/master
branch builds. Previously, the function would skip checking for the .so
file entirely for main/master versions, causing the final error check to
fail when found=false.

Now the check:
1. Verifies pg_lake.so exists for main/master versions
2. Records the version and sets found=true if installed
3. Logs (doesn't error) if not built for unsupported PG versions
4. Only errors for tagged versions that should exist but don't

This allows the build to pass install checks when using PG_LAKE_VERSIONS=main.

Author: minkimipt

cicd/shared.sh

@@ -197,8 +197,19 @@ check_pg_lake() {
 	record_ext_version pg_lake "$pg" ""
 
 	for ver in $PG_LAKE_VERSIONS; do
+		# For main/master branches, check if installed but don't verify specific version
 		if [[ "$ver" = master || "$ver" = main ]]; then
-			log "skipping looking for pg_lake-$ver"
+			if [ -s "$lib/pg_lake.so" ]; then
+				found=true
+				record_ext_version pg_lake "$pg" "$ver"
+			else
+				unsupported_reason="$(supported_pg_lake "$pg" "$ver")"
+				if [ -n "$unsupported_reason" ]; then
+					log "skipped: pg_lake-$ver: $unsupported_reason"
+				else
+					log "pg_lake-$ver not built for pg$pg (skipping version check for main/master)"
+				fi
+			fi
 			continue
 		fi