Prepare migration to monorepo

--HG--
branch : 6.0

.hgtags

@@ -15,3 +15,37 @@ a6e59e1c9b7981c3ce55f2706fffc4d6c4ecb2f2 5.4.0
 82f6469734f62913831c916e4806176cbc3aec45 5.6.0
 25be0cc57f3a7d62c776e6c8d909b4cfc66e327a 5.8.0
 19d51ff65558dd670c32a1ce0b50b26720858330 6.0.0
+0000000000000000000000000000000000000000 2.8.0
+94bdfd1cd5e2c99c3959c1d64a724d9a3ece3105 product_attribute-2.8.0
+0000000000000000000000000000000000000000 3.0.0
+1c8453af3faa524d6b1691e16ff5c309c3dc9924 product_attribute-3.0.0
+0000000000000000000000000000000000000000 3.2.0
+c32af032295ba1c9c350149fdb72cc75e2f8e879 product_attribute-3.2.0
+0000000000000000000000000000000000000000 3.4.0
+a415efe2f8858331918fd21671c10710ea168bf8 product_attribute-3.4.0
+0000000000000000000000000000000000000000 3.6.0
+d5eb319f2f8bdb2bcaf48cac085242f2a8938f52 product_attribute-3.6.0
+0000000000000000000000000000000000000000 3.8.0
+ecde7f8aea8da31144867dab649e53c2b1c9028c product_attribute-3.8.0
+0000000000000000000000000000000000000000 4.0.0
+d17b4e7a6a24536364a490bee9403f1e7b988c09 product_attribute-4.0.0
+0000000000000000000000000000000000000000 4.2.0
+dc8bc00f7851f92ad319775b8a0e212fd6e17cfb product_attribute-4.2.0
+0000000000000000000000000000000000000000 4.4.0
+e055d1d375a2b4247cceb655068197b5655a85d4 product_attribute-4.4.0
+0000000000000000000000000000000000000000 4.6.0
+864a76d7532908811155e244d7332e793fe2971d product_attribute-4.6.0
+0000000000000000000000000000000000000000 4.8.0
+d75431d46ffe498600ca25243b3f17e83f9181dc product_attribute-4.8.0
+0000000000000000000000000000000000000000 5.0.0
+593f4c628132990b0494e76e4397435584ab6694 product_attribute-5.0.0
+0000000000000000000000000000000000000000 5.2.0
+556786caa13a0de23f83b8631dec50dbdb1b227c product_attribute-5.2.0
+0000000000000000000000000000000000000000 5.4.0
+a6e59e1c9b7981c3ce55f2706fffc4d6c4ecb2f2 product_attribute-5.4.0
+0000000000000000000000000000000000000000 5.6.0
+82f6469734f62913831c916e4806176cbc3aec45 product_attribute-5.6.0
+0000000000000000000000000000000000000000 5.8.0
+25be0cc57f3a7d62c776e6c8d909b4cfc66e327a product_attribute-5.8.0
+0000000000000000000000000000000000000000 6.0.0
+19d51ff65558dd670c32a1ce0b50b26720858330 product_attribute-6.0.0