Allow languages to be updated from any directory

Now these commands will work:
python .\lang\update-po.py
python .\lang\update-pot.py

When current working directory is
.\Prusa-Firmware\

Previously, you'd need to call the
script within the lang folder.

lang/lang-extract.py

@@ -12,7 +12,7 @@ from pathlib import Path, PurePosixPath
 FILE_LIST: list[Path] = []
 
 # Absolute path
-BASE_DIR: Path = Path.cwd().resolve()
+BASE_DIR: Path = Path.absolute(Path(__file__).parent)
 PO_DIR: Path = BASE_DIR / "po"
 
 # Pathlib can't change the working directory yet

lang/update-po.py

@@ -12,7 +12,7 @@ from pathlib import Path
 import polib
 from polib import POFile
 
-BASE_DIR: Path = Path.cwd()
+BASE_DIR: Path = Path.absolute(Path(__file__).parent)
 PO_DIR: Path = BASE_DIR / "po"
 PO_FILE_LIST: list[Path] = []
 POT_REFERENCE: POFile = polib.pofile(PO_DIR/'Firmware.pot')

lang/update-pot.py

@@ -15,7 +15,7 @@ import shutil
 import subprocess
 from subprocess import CalledProcessError
 
-BASE_DIR: Path = Path.cwd().resolve()
+BASE_DIR: Path = Path.absolute(Path(__file__).parent)
 PROJECT_DIR: Path = BASE_DIR.parent
 PO_DIR: Path = BASE_DIR / "po"
 
@@ -45,11 +45,12 @@ def main():
             print(error)
 
     # Run the lang-extract.py script
+    SCRIPT_PATH = BASE_DIR.joinpath("lang-extract.py")
     try:
         subprocess.check_call(
             [
                 "python",
-                "lang-extract.py",
+                SCRIPT_PATH,
                 "--no-missing",
                 "-s",
                 "-o",