Fixs isaaclab.sh to detect isaacsim_version accurately 4.5 or >= 5.0 (#3139)

# Description

Current is_isaacsim_version_4_5() sometimes mis-detects 5.0 when running
4.5 (e.g., Docker/symlinked installs), causing the conda bootstrap to
pick Python 3.11 instead of 3.10.

This pr ensures determining the isaacsim version following below steps

1. Read ${ISAACLAB_PATH}/_isaac_sim/VERSION (symlink/binary install).

2. If unknown, import isaacsim and read ../../VERSION next to the
package. (pip installation)

3. If still unknown, fall back to
importlib.metadata.version("isaacsim").

I tested locally to work with 4.5 pip or binary install.

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- Bug fix (non-breaking change which fixes an issue)

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## Checklist

- [x] I have run the [`pre-commit` checks](https://pre-commit.com/) with
`./isaaclab.sh --format`
- [ ] I have made corresponding changes to the documentation
- [x] My changes generate no new warnings
- [ ] I have added tests that prove my fix is effective or that my
feature works
- [x] I have updated the changelog and the corresponding version in the
extension's `config/extension.toml` file
- [x] I have added my name to the `CONTRIBUTORS.md` or my name already
exists there

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isaaclab.sh

@@ -43,33 +43,48 @@ install_system_deps() {
     fi
 }
 
+# Returns success (exit code 0 / "true") if the detected Isaac Sim version starts with 4.5,
+# otherwise returns non-zero ("false"). Works with both symlinked binary installs and pip installs.
 is_isaacsim_version_4_5() {
+    local version=""
     local python_exe
     python_exe=$(extract_python_exe)
 
-    # 1) Try the VERSION file
-    local sim_file
-    sim_file=$("${python_exe}" -c "import isaacsim; print(isaacsim.__file__)" 2>/dev/null) || return 1
-    local version_path
-    version_path=$(dirname "${sim_file}")/../../VERSION
-    if [[ -f "${version_path}" ]]; then
-        local ver
-        ver=$(head -n1 "${version_path}")
-        [[ "${ver}" == 4.5* ]] && return 0
+    # 0) Fast path: read VERSION file from the symlinked _isaac_sim directory (binary install)
+    # If the repository has _isaac_sim → <IsaacSimRoot> symlink, the VERSION file is the simplest source of truth.
+    if [[ -f "${ISAACLAB_PATH}/_isaac_sim/VERSION" ]]; then
+        # Read first line of the VERSION file; don't fail the whole script on errors.
+        version=$(head -n1 "${ISAACLAB_PATH}/_isaac_sim/VERSION" || true)
     fi
 
-    # 2) Fallback to importlib.metadata via a here-doc
-    local ver
-    ver=$("${python_exe}" <<'PYCODE' 2>/dev/null
+    # 1) Package-path probe: import isaacsim and walk up to ../../VERSION (pip or nonstandard layouts)
+    # If we still don't know the version, ask Python where the isaacsim package lives
+    if [[ -z "$version" ]]; then
+        local sim_file=""
+        # Print isaacsim.__file__; suppress errors so set -e won't abort.
+        sim_file=$("${python_exe}" -c 'import isaacsim, os; print(isaacsim.__file__)' 2>/dev/null || true)
+        if [[ -n "$sim_file" ]]; then
+            local version_path
+            version_path="$(dirname "$sim_file")/../../VERSION"
+            # If that VERSION file exists, read it.
+            [[ -f "$version_path" ]] && version=$(head -n1 "$version_path" || true)
+        fi
+    fi
+
+    # 2) Fallback: use package metadata via importlib.metadata.version("isaacsim")
+    if [[ -z "$version" ]]; then
+        version=$("${python_exe}" <<'PY' 2>/dev/null || true
 from importlib.metadata import version, PackageNotFoundError
 try:
     print(version("isaacsim"))
 except PackageNotFoundError:
-    import sys; sys.exit(1)
-PYCODE
-) || return 1
+    pass
+PY
+)
+    fi
 
-    [[ "${ver}" == 4.5* ]]
+    # Final decision: return success if version begins with "4.5", 0 if match, 1 otherwise.
+    [[ "$version" == 4.5* ]]
 }
 
 # check if running in docker