Ignore compression value from BMP info dictionary when saving as TIFF

[radarhere]

Helps #6230

BmpImagePlugin sets the info dictionary "compression" to an integer.

Pillow/src/PIL/BmpImagePlugin.py

Lines 70 to 72 in c6637bc

	COMPRESSIONS = {"RAW": 0, "RLE8": 1, "RLE4": 2, "BITFIELDS": 3, "JPEG": 4, "PNG": 5}
	for k, v in COMPRESSIONS.items():
	vars()[k] = v

Pillow/src/PIL/BmpImagePlugin.py

Line 95 in c6637bc

file_info["compression"] = self.RAW

Pillow/src/PIL/BmpImagePlugin.py

Line 252 in c6637bc

self.info["compression"] = file_info["compression"]

However, when TiffImagePlugin is saving, it expects a string.

Pillow/src/PIL/TiffImagePlugin.py

Lines 1571 to 1578 in c6637bc

	compression = encoderinfo.get("compression", im.info.get("compression"))
	if compression is None:
	compression = "raw"
	elif compression == "tiff_jpeg":
	# OJPEG is obsolete, so use new-style JPEG compression instead
	compression = "jpeg"
	elif compression == "tiff_deflate":
	compression = "tiff_adobe_deflate"

This leads to an error. This PR instead ignores integer compression values from the info dictionary when saving as a TIFF.